Synthesis and crystal structures of N,2,4,6-tetra-methyl-anilinium tri-fluoro-methane-sulfonate and N-iso-propyl-idene-N,2,4,6-tetra-methyl-anilinium tri-fluoro-methane-sulfonate.

Two 2,4,6-tri-methyl-aniline-based trifuloro-methane-sulfonate (tri-fluoro-methane-sulfonate) salts were synthesized and characterized by single-crystal X-ray diffraction. N,2,4,6-Tetra-methyl-anilinium tri-fluoro-methane-sulfonate, [C10H14NH2 +][CF3O3S-] (1), was synthesized via methyl-ation of 2,4,6-tri-methyl-aniline. N-Iso-propyl-idene-N,2,4,6-tetra-methyl-anilinium tri-fluoro-meth-ane-sulfonate, [C13H20N+][CF3O3S-] (2), was synthesized in a two-step reaction where the imine, N-iso-propyl-idene-2,4,6-tri-methyl-aniline, was first prepared via a dehydration reaction to form the Schiff base, followed by methyl-ation using methyl tri-fluoro-methane-sulfonate to form the iminium ion. In compound 1, both hydrogen bonding and π-π inter-actions form the main inter-molecular inter-actions. The primary inter-action is a strong N-H⋯O hydrogen bond with the oxygen atoms of the tri-fluoro-methane-sulfonate anions bonded to the hydrogen atoms of the ammonium nitro-gen atom to generate a one-dimensional chain. The [C10H14NH2 +] cations form dimers where the benzene rings form a π-π inter-action with a parallel-displaced geometry. The separation distance between the calculated centroids of the benzene rings is 3.9129 (8) Å, and the inter-planar spacing and ring slippage between the dimers are 3.5156 (5) and 1.718 Å, respectively. For 2, the [C13H20N+] cations also form dimers as in 1, but with the benzene rings highly slipped. The distance between the calculated centroids of the benzene rings is 4.8937 (8) Å, and inter-planar spacing and ring slippage are 3.3646 (5) and 3.553 Å, respectively. The major inter-molecular inter-actions in 2 are instead a series of weaker C-H⋯O hydrogen bonds [C⋯O distances of 3.1723 (17), 3.3789 (18), and 3.3789 (18) Å], an inter-action virtually absent in the structure of 1. Fluorine atoms are not involved in strong directional inter-actions in either structure.

Crystal structure of an indium-salicyl-hydroximate complex cation: [In4(H2shi)8(H2O)6](NO3)4·8.57H2O.

The synthesis and crystal structure for the title compound, hexa-aqua-hexa-kis(µ-2-hy-droxy-benzene-carbo-hydrox-a-mato)bis-(2-hy-droxy-benzene-carbo-hydrox-a-m-ato)tetra-indium(III) tetra-nitrate 8.57-hydrate + unknown solvent, [In4(H2shi)8(H2O)6](NO3)4·8.57H2O·solvent, where H2shi- is salicylhydrox-imate (C7H5NO3), are reported. The complex cation of the structure, [In4(H2shi)8(H2O)6]4+, is a dimer with a step-like topology and possesses an inversion center that relates each [In2(H2shi)4(H2O)3]2+ side of the complex cation. Each InIII ion is seven-coordinate with a penta-gonal-bipyramidal geometry, and the salicyl-hydroximate ligands have a 1- charge as only the oxime oxygen of the ligand is deprotonated. Four inter-stitial nitrate anions maintain the charge balance of the compound. One of the nitrate anions (and its symmetry equivalent) is disordered over two different orientations with an occupancy ratio of 0.557 (7) to 0.443 (7). The inter-stitial solvent water mol-ecules show substantial disorder. Approximately 8.57 water mol-ecules per formula unit were refined as disordered and partially occupied, while a suitable model could not be devised for the other extensively disordered solvent mol-ecules (water and possibly methanol as this was the synthesis solvent). Thus, these latter solvent mol-ecules were instead treated with the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9-18.] as implemented in the program PLATON, and the procedure corrected for 151 electrons within solvent-accessible voids of 367 Å3.

Visible and near-infrared emitting heterotrimetallic lanthanide-aluminum-sodium 12-metallacrown-4 compounds: discrete monomers and dimers.

The luminescence properties of two types of heterotrimetallic aluminum-lanthanide-sodium 12-metallacrown-4 compounds are presented here, LnNa(ben)4[12-MCAl(III)N(shi)-4] (LnAl4Na) and {LnNa[12-MCAl(III)N(shi)-4]}2(iph)4 (Ln2Al8Na2), where Ln = GdIII, TbIII, ErIII, and YbIII, MC is metallacrown, ben- is benzoate, shi3- is salicylhydroximate, and iph2- is isophthalate. The aluminum-lanthanide-sodium metallacrowns formed with benzoate are discrete monomers while, upon replacement of the benzoate with the dicarboxylate isophthalate, two individual metallacrowns can be joined to form a dimer. In the solid state, the terbium version of each structure type displays emission in the visible region, and the erbium and ytterbium complexes emit in the near-infrared. The luminescence lifetimes (τobs) and quantum yields have been collected under ligand excitation (QLLn) for both LnAl4Na monomers and Ln2Al8Na2 dimers. Several of these values tend to be shorter (luminescence lifetimes) and smaller (quantum yields) than the corresponding values recorded for the structurally similar gallium-lanthanide monomer and dimer 12-MC-4 molecules. However, the quantum yield value recorded for the visible emitting Tb2Al8Na2 dimer, 43.9%, is the highest value observed in the solid state to date for a TbIII based metallacrown.

Synthesis and crystal structure of a heterobimetallic nickel-manganese 12-metallacrown-4 methanol disolvate monohydrate compound.

The synthesis and crystal structure of the title compound [systematic name: di-µ-acetato-tetra-kis-(µ4-N,2-dioxido-benzene-1-carboximidato)hexa-methano-ltetra-manganese(III)nickel(II) methanol disolvate monohydrate], [Mn4Ni(C7H4NO3)4(C2H3O2)2(CH4O)6]·2CH4O·H2O or Ni(OAc)2[12-MCMn(III)N(shi)-4](CH3OH)6·2CH3OH·H2O, where MC is metallacrown, -OAc is acetate, and shi3- is salicyl-hydroximate, are reported. The macrocyclic metallacrown is positioned on an inversion center located on the NiII ion that resides in the central MC cavity. The macrocycle consists of an MnIII-N-O repeat unit that recurs four times to generate an overall square-shaped mol-ecule. Both the NiII and MnIII ions are six-coordinate with an octa-hedral geometry. In addition, the MnIII ions possess an elongated Jahn-Teller distortion along the z-axis of the coordination environment. The inter-stitial water mol-ecule is slightly offset from and disordered about an inversion center.

Crystal structures of three anionic lanthanide-aluminium [3.3.1] metallacryptate complexes.

The three isomorphous [3.3.1] metallacryptate complexes bis-(pyridinium) di-aqua-dipyridine-hexa-kis-[µ3-salicyl-hydroximato(3-)]bis-[µ2-salicyl-hydroxim-ato(1-)]hexa-aluminiumgadolinium-pyridine-water (1/7.396/1), (C5H6N)2[GdAl6(C7H6NO3)2(C7H4NO3)7(C5H5N)1.855(H2O)2]·7.396C5H5N·H2O or [Hpy]2[GdAl6(H2shi)2(shi)7(py)1.855(H2O)2]·7.396py·H2O, 1, bis-(pyridinium) di-aqua-dipyridine-hexa-kis-[µ3-salicyl-hydroximato(3-)]bis-[µ2-salicyl-hydroxim-ato(1-)]hexa-aluminiumdysprosium-pyridine-water (1/7.429/1), (C5H6N)2[DyAl6(C7H6NO3)2(C7H4NO3)7(C5H5N)1.855(H2O)2]·7.429C5H5N·H2O or [Hpy]2[DyAl6(H2shi)2(shi)7(py)1.891(H2O)2]·7.429py·H2O, 2, and bis-(pyrid-in-ium) di-aqua-dipyridine-hexa-kis-[µ3-salicyl-hydroximato(3-)]bis-[µ2-salicyl-hydrox-imato(1-)]hexa-aluminiumytterbium-pyridine-water (1/7.386/1), (C5H6N)2[YbAl6(C7H6NO3)2(C7H4NO3)7(C5H5N)1.855(H2O)2]·7.429C5H5N·H2O or [Hpy]2[YbAl6(H2shi)2(shi)7(py)1.818(H2O)2]·7.386py·H2O, 3, where Hpy+ is pyridinium, shi3- is salicyl-hydroximate, and py is pyridine, consist of an aluminium-based metallacryptand that captures an Ln III ion in the central cavity. The metallacryptand portions are comprised of an Al-N-O repeat unit; thus, they can be considered three-dimensional metallacrowns. The encapsulated Ln III ions are nine-coordinate with a spherical capped-square-anti-prism geometry, while the six AlIII ions are all octa-hedral. Four of the AlIII ions are chiral centers with 2 Δ and 2 Λ stereoconfigurations. The remaining two AlIII ions have trans chelate rings from two different shi3- ligands. For 1-3, a section of the main mol-ecule is disordered induced by the presence or absence of a pyridine ligand coordinated to one of the AlIII ions. In the absence of the pyridine moiety, an H2shi- ligand moves into the space otherwise occupied by the pyridine and the phenol oxygen atom coordinates to the AlIII ion. The movement of the H2shi- ligand induces movement for the Ln III ion, for another AlIII ion that also binds the same H2shi- ligand, and for one of the shi3- ligands coordinated to the latter AlIII ion. For 1-3 the occupancy ratio of the metallacryptand portions refined to 0.8550 (13):0.1450 (13), to 0.8909 (13):0.1091 (13), and to 0.8181 (14):0.1819 (14), respectively.

Crystal structures of two heterotrimetallic dysprosium-manganese-sodium 12-metallacrown-4 complexes with the bridging ligands 3-hy-droxy-benzoate and 4-hy-droxy-benzoate.

The syntheses and crystal structures for the compounds tetra-µ-aqua--tetra-kis-{2-[aza-nid-yl-ene(oxido)meth-yl]phenolato}tetra-kis-(µ2-3-hy-droxy-benzoato)dys-pro-s-ium(III)-tetra-manganese(III)sodium(I) N,N-di-methyl-acetamide deca-solvate, [DyMn4Na(C7H5O3)4(C7H4NO2)4(H2O)4]·10C4H9NO or [DyIIINa(4-OHben)4{12-MCMn(III)N(shi)-4}(H2O)4]·10DMA, 1, and tetra-µ-aqua--tetra-kis-{2-[aza-nid-yl-ene(oxido)meth-yl]phenolato}tetra-kis-(µ2-3-hy-droxy-benzoato)dys-pros-ium(III)tetra-manganese(III)sodium(I) N,N-di-methylformamide tetra-solvate, [DyMn4Na(C7H5O3)4(C7H4NO2)4(H2O)4]·4C3H7NO or [DyIIINa(3-OHben)4{12-MCMn(III)N(shi)-4}(H2O)4]·4DMF, 2, and where MC is metallacrown, shi3- is salicyl-hydroximate, 3-OHben is 3-hy-droxy-benzoate, DMA is N,N-di-methyl-acetamide, 4-OHben is 4-hy-droxy-benzoate, and DMF is N,N-di-methyl-formamide, are reported. For both 1 and 2, the macrocyclic metallacrown consists of an [MnIII-N-O] ring repeat unit, and the domed metallacrown captures two ions in the central cavity: a DyIII ion on the convex side of the metallacrown and an Na+ ion the concave side. The MnIII ions are six-coordinate with an elongated tetra-gonally distorted octa-hedral geometry. Both the DyIII and Na+ ions are eight-coordinate. The DyIII ions possess a square-anti-prismatic geometry, while the Na+ ions have a distorted biaugmented trigonal-prismatic geometry. Four 3-hy-droxy-benzoate or 4-hy-droxy-benzoate ligands bridge each MnIII ion to the central DyIII ion. For 1, whole-mol-ecule disorder is observed for the main mol-ecule, excluding only the DyIII and Na+ ions, and the occupancy ratio refined to 0.8018 (14):0.1982 (14). Three DMA mol-ecules were refined as disordered with two in general positions by an approximate 180° rotation and the third disordered twice by general disorder as well as by an exact 180° rotation about a twofold axis that bis-ects it. The occupancy ratios refined to 0.496 (8):0.504 (8), 0.608 (9):0.392 (9), and 2×0.275 (7):2×0.225 (7), respectively. For 2, segments of the metallacrown are disordered including the DyIII ion, one of the Mn ions, two of the Mn-bound 4-hy-droxy-benzoate ligands, the Mn-bridging salicyl-hydroximate ligand, and portions of the remaining three shi3- ligands. The occupancy ratio for the metallacrown disorder refined to 0.849 (9):0.151 (9). Two DMF solvent mol-ecules are also disordered, each over two orientations. The disorder ratios refined to 0.64 (3):0.36 (3) and to 0.51 (2):0.49 (2), respectively. For 2, the crystal under investigation was refined as a non-merohedric twin by a 90° rotation around the real a axis [twin ratio 0.9182 (8):0.0818 (8)].

Crystal structures of two dysprosium-aluminium-sodium [3.3.1] metallacryptates that form two-dimensional sheets.

The two [3.3.1] metallacryptate complexes, namely, poly[[µ3-acetato-hexa-kis-(µ-N,N-di-methyl-formamide)-bis-(N,N-di-methyl-formamide)bis-[salicyl-hydroxi-mato(2-)]hepta-kis-[salicyl-hydrox-im-ato(3-)]hexa-aluminium(III)dysprosium(III)penta-sodium(I)] N,N-di-methyl-formamide tetra-solvate monohydrate], [DyAl6Na5(OAc)(Hshi)2(shi)7(DMF)8]·4DMF·H2O or {[DyAl6Na5(C7H5NO3)2(C7H4NO3)7(C2H3O2)(C3H7NO)8]·4C3H7NO·H2O} n , 1, and poly[[di-µ4-acetato-nona-kis-(µ-N,N-di-methyl-form-amide)-octa-kis-(N,N-di-methyl-formamide)tetra-kis-[sali-cyl-hydroximato(2-)]tetra-deca-kis-[salicyl-hydroximato(3-)]dodeca-aluminium(III)didysprosium(III)deca-sodium(I)] N,N-di-methyl-form-amide 6.335-solvate], [DyAl6Na5(OAc)(Hshi)2(shi)7(DMF)8.5]2·6.335DMF or {[Dy2Al12Na10(C7H5NO3)4(C7H4NO3)14(C2H3O2)2(C3H7NO)17]·6.335C3H7NO} n , 2, where shi3- is salicyl-hydroximate and DMF is N,N-di-methyl-formamide, both consist of an aluminium-based metallacryptand. In 1 and 2, the metallacryptand encapsulates a dysprosium(III) ion in the central cavity, and the resulting metallacryptates are connected to each other via sodium-DMF linkages to generate a two-dimensional sheet. The metallacryptates of 1 and 2 are the three-dimensional analogues of metallacrowns as the metallacryptates contain a metal-nitro-gen-oxygen cyclic repeat unit throughout the complexes. For 1 the building block of the two-dimensional sheet is comprised of only one type of metallacryptate, which is connected to four neighboring metallacryptates via four sodium-DMF linkages. In 2, the building block is a dimeric unit of two metallacryptates. Each dimeric metallacryptate unit is connected to four other dimeric units via six sodium-DMF linkages. The two metallacryptates of each dimeric unit can be considered enanti-omers of each other. In both 1 and 2, chirality is imparted to the metallacryptate due to the Λ and Δ propeller configurations of the four octa-hedral aluminium ions of the metallacryptand shell.

Slow Magnetic Relaxation of a 12-Metallacrown-4 Complex with a Manganese(III)-Copper(II) Heterometallic Ring Motif.

The heterobimetallic metallacrown (MC), (TMA)2{Mn(OAc)2[12-MCMn(III)Cu(II)N(shi)-4](CH3OH)}·2.90CH3OH, 1, where TMA+ is tetramethylammonium, -OAc is acetate, and shi3- is salicylhydroximate, consists of a MnII ion captured in the central cavity and alternating unambiguous and ordered manganese(III) and copper(II) sites about the MC ring, a first for the archetypal MC structure design. DC-magnetometry characterization and subsequent simulation with the Spin Hamiltonian H = -J1(s1 + s3)·s5 - J2(s2 + s4)·s5 - J3Σi=14si·si+1 + d(sz,12 + sz,32) + µBΣj=15gjsj·B indicates an S = 5/2 ground state and a sizable axial zero-field splitting on MnIII. AC-susceptibility measurements reveal that 1 displays slow magnetization relaxation akin to single-molecule magnet (SMM) behavior.

Synthesis and crystal structure of two manganese-based 12-metallacrown-4 complexes: Na2(3-chloro-benzoate)2[12-MCMn(III)N(shi)-4](DMF)6 and MnNa(3-chloro-benzoate)3[12-MCMn(III)N(shi)-4](DMF)(H2O)4·4DMF·0.72H2O.

Similar synthetic schemes yield two different metallacrown (MC) complexes: bis-(µ-3-chloro-benzoato)hexa-kis-(di-methyl-formamide)-tetra-kis-(µ4-N,2-dioxido-benzene-1-carboximidato)tetra-manganese(III)disodium(I), [Mn4Na2(C7H4ClO2)2(C7H4NO3)4(C3H7NO)6] or Na2(3-chloro-benzoate)2[12-MCMn(III)N(shi)-4](DMF)6, 1, and tetra-µ-aqua-tris-(µ-3-chloro-benzoato)(di-methyl-formamide)-tetra-kis-(µ4-N,2-dioxido-benzene-1-carboximidato)penta-manganese(III)sodi-um(I) di-methyl-formamide tetra-solvate 0.72-hydrate, [Mn5Na(C7H4ClO2)3(C7H4NO3)4(C3H7NO)(H2O)4]·4C3H7NO·0.718H2O or MnNa(3-chloro-benzo-ate)3[12-MCMn(III)N(shi)-4](DMF)(H2O)4·4DMF·0.72H2O, 2, where shi3- is salicyl-hydrox-imate and DMF is N,N-di-methyl-formamide. Both complexes have the same framework consisting of four MnIII ions in the MC ring and four shi3- ligands, resulting in an overall square-shaped mol-ecule. The MnIII ions are either five- or six-coordinate with elongated bond lengths in the apical or axial direction, respectively. The structure of 1 is nearly planar, and the MC binds two Na+ ions on opposite faces of the MC central cavity. The 3-chloro-benzoate anions also bind on opposite faces of the MC and form bridges between the central Na+ ions and the ring MnIII ions. For 1 the metallacrown mol-ecule, except for the central Na+ ion, exhibits whole mol-ecule disorder over two sets of sites. Both moieties are centrosymmetric and are related to each other by a pseudo-mirror operation with opposite sense of rotation around the Na⋯Na axis. The occupancy ratio of the main disorder of the metallacrown mol-ecules and 3-chloro-benzoate anions refined to 0.9276 (9):0.0724 (9). The structure of 2 is slightly domed, and the MC binds both an MnII ion and an Na+ ion in the MC central cavity. The MnII ion is located on the convex side of the MC, while the Na+ ion binds to the concave side. Complex 2 represents the first instance of a [12-MCMn(III)N(shi)-4] mol-ecule binding both 3d transition metal and alkali metal ions in the central cavity. In addition, three 3-chloro-benzoate anions bind on the convex side of the MC and connect the MnII ion to three of the ring MnIII ions.

Synthesis and crystal structure of a penta-copper(II) 12-metallacrown-4: cis-di-aqua-tetra-kis-(di-methyl-formamide-κO)manganese(II) tetra-kis-(µ3-N,2-dioxido-benzene-1-carboximidate)penta-copper(II) di-methyl-formamide monosolvate.

The title compound, [Mn(C3H7NO)4(H2O)2][Cu5(C7H4NO3)4]·C3H7NO or cis-[Mn(H2O)2(DMF)4]{Cu[12-MCCu(II)N(shi)-4]}·DMF, where MC is metallacrown, shi3- is salicyl-hydroximate, and DMF is N,N-di-methyl-formamide, crystallizes in the monoclinic space group P21/n. Two crystallographically independent metallacrown anions are present in the structure, and both anions exhibit minor main mol-ecule disorder by an approximate (non-crystallographic) 180° rotation with occupancy ratios of 0.9010 (9) to 0.0990 (9) for one anion and 0.9497 (8) to 0.0503 (8) for the other. Each penta-copper(II) metallacrown contains four CuII ions in the MC ring and a CuII ion captured in the central cavity. Each CuII ion is four-coordinate with a square-planar geometry. The anionic {Cu[12-MCCu(II)N(shi)-4]}2- is charged-balanced by the presence of a cis-[Mn(H2O)2(DMF)4]2+ cation located in the lattice. In addition, the octa-hedral MnII counter-cation is hydrogen bonded to both MC anions via the coordinated water mol-ecules of the MnII ion. The water mol-ecules form hydrogen bonds with the phenolate and carbonyl oxygen atoms of the shi3- ligands of the MCs.

Elucidation of 1H NMR Paramagnetic Features of Heterotrimetallic Lanthanide(III)/Manganese(III) 12-MC-4 Complexes.

The paramagnetic one-dimensional 1H NMR spectra of twelve LnIIINaI(OAc)4[12-MCMnIII(N)shi-4] complexes, where LnIII is PrIII-YbIII (except PmIII) and YIII, are reported. Their solid-state isostructural nature is confirmed in methanol-d4 solution, as a similar pattern in the 1H NMR spectra is observed along the series. Notably, a relatively well-resolved spectrum is reported for the GdIII complex. The chemical shift data are analyzed using the "all lanthanides" method, and the Fermi contact and pseudo-contact contributions are calculated for the lanthanide-induced shift (LIS). For the TbIII-YbIII complexes, the pseudo-contact contributions are typically 1 order of magnitude higher than the Fermi contact contributions; however, for the GdIII complex, the Fermi contact is the main contribution to the paramagnetic chemical shift. For the methyl protons of the axial acetate (-OAc) ligands, the LIS is opposite in sign, with respect to that of the aromatic salicylhydroximate (shi3-) protons, because of structural rearrangements that occur upon dissociation of the NaI cation in solution. The calculated crystal field parameters (BLn) for the TbIII (360 cm-1), DyIII (250 cm-1), HoIII (380 cm-1), ErIII (410 cm-1), TmIII (620 cm-1), and YbIII (380 cm-1) complexes are not constant, likely as a consequence of the inaccuracy of the Bleaney's constants and, to a smaller extent, the small structural changes that occur in solution. Overall, the metallacrown scaffold retains structural integrity and similarity in solution for the entire series; however, small structural features, which do not affect the overall similarity, do likely occur.

The Nature of the Bridging Anion Controls the Single-Molecule Magnetic Properties of DyX4M 12-Metallacrown-4 Complexes.

A family of DyX4M(12-MCMnIII(N)shi-4) compounds were synthesized and magnetically characterized (X = salicylate, acetate, benzoate, trimethylacetate, M = NaI or KI). The bridging ligands were systematically varied while keeping the remainder of the MC-geometry constant. The type of monovalent cation, necessary for charge balance, was also altered. The dc magnetization and susceptibility of all compounds were similar across the series. Regardless of the identity of the countercation, the Dy(Hsal)4M 12-MC-4 compounds were the only compounds to show frequency-dependent ac magnetic susceptibility, a hallmark of single-molecule magnetism. This indicates that the nature of the bridging ligand in the 12-MCMnIII(N)shi-4 compounds strongly affects the out-of-phase magnetic properties. The SMM behavior appears to correlate with the pKa of the bridging ligand.

Crystal structure of tetra-aqua-(di-methyl-formamide)-tetra-kis-(µ-N,2-dioxido-benzene-1-carboximidato)tetra-kis-(µ-tri-methyl-acetato)-tetra-manganese(III)sodiumyttrium-di-methyl-formamide-water (1/8.04/0.62).

The synthesis and crystal structure for the title compound, [YNaMn4(C7H4NO3)4(C5H9O2)4(H2O)3.76(C3H7NO)0.24]·8.04C3H7NO·0.62H2O or [Y(III)Na(OTMA)4[12-MCMn(III)N(shi)-4](H2O)3.76(DMF)0.24·8.04DMF·0.62H2O, where OTMA is tri-methyl-acetate, MC is metallacrown, shi(3-) is salicyl-hydroximate, and DMF is N,N-di-methyl-formamide, is reported. The macrocyclic metallacrown consists of an -[Mn(III)-N-O]4- ring repeat unit, and the metallacrown captures one Y(III) ion and one Na(I) ion in the central cavity on opposite faces of the metallacrown. Overall the metallacrown is domed towards the side of the Na(I) ion. Both the Y(III) and Na(I) ions are eight-coordinate, and the tri-methyl-acetate anions bridge the central Y(III) to each ring Mn(III) ion. The ring Mn(III) ions are six-coordinate with a tetra-gonally distorted octa-hedral geometry.

Controllable formation of heterotrimetallic coordination compounds: systematically incorporating lanthanide and alkali metal ions into the manganese 12-metallacrown-4 framework.

The inclusion of Ln(III) ions into the 12-MC-4 framework generates the first heterotrimetallic complexes of this molecular class. The controllable and deliberate preparations of these compounds are demonstrated through 12 crystal structures of the Ln(III)M(I)(OAc)4[12-MCMn(III)(N)shi-4](H2O)4·6DMF complex, where OAc(-) is acetate, shi(3-) is salicylhydroximate, and DMF is N,N-dimethylformamide. Compounds 1-12 have M(I) as Na(I), and Ln(III) can be Pr(III) (1), Nd(III) (2), Sm(III) (3), Eu(III) (4), Gd(III) (5), Tb(III) (6), Dy(III) (7), Ho(III) (8), Er(III) (9), Tm(III) (10), Yb(III) (11), and Y(III) (12). An example with M(I) = K(I) and Ln(III) = Dy(III) is also reported (Dy(III)K(OAc)4[12-MCMn(III)(N)shi-4](DMF)4·DMF (14)). When La(III), Ce(III), or Lu(III) is used as the Ln(III) ions to prepare the Ln(III)Na(I)(OAc)4[12-MCMn(III)(N)shi-4] complex, the compound Na2(OAc)2[12-MCMn(III)(N)shi-4](DMF)6·2DMF·1.60H2O (13) results. For compounds 1-12, the identity of the Ln(III) ion affects the 12-MCMn(III)(N)shi-4 framework as the largest Ln(III), Pr(III), causes an expansion of the 12-MCMn(III)(N)shi-4 framework as demonstrated by the largest metallacrown cavity radius (0.58 Å for 1 to 0.54 Å for 11), and the Pr(III) causes the 12-MCMn(III)(N)shi-4 framework to be the most domed structure as evident in the largest average angle about the axial coordination of the ring Mn(III) ions (103.95° for 1 to 101.69° for 11). For 14, the substitution of K(I) for Na(I) does not significantly affect the 12-MCMn(III)(N)shi-4 framework as many of the structural parameters such as the metallacrown cavity radius (0.56 Å) fall within the range of compounds 1-12. However, the use of the larger K(I) ion does cause the 12-MCMn(III)(N)shi-4 framework to become more planar as evident in a smaller average angle about the axial coordination of the ring Mn(III) ions (101.35°) compared to the analogous Dy(III)/Na(I) (7) complex (102.40°). In addition to broadening the range of structures available through the metallacrown analogy, these complexes allow for the mixing and matching of a diverse range of metals that might permit the fine-tuning of molecular properties where one day they may be exploited as magnetic materials or luminescent agents.

Crystal structure of di-µ-chloro-acetato-hexa-kis-(di-methyl-formamide)-tetra-kis-(µ-N,2-dioxido-benzene-1-carboximidato)tetra-manganese(III)disodium dimethyl-formamide disolvate.

The synthesis, crystal structure, and FT-IR data for the title compound, [Na2Mn4(C2H2ClO2)2(C7H4NO3)4(C3H7NO)6]·2C3H7NO or Na2(O2CCH2Cl)2[12-MCMn(III) N(shi)-4](DMF)6·2DMF, where MC is metallacrown, shi(3-) is salicyl-hydroximate, and DMF is N,N-di-methyl-formamide, is reported. The macrocyclic metallacrown consists of an -[Mn(III)-N-O]4- ring repeat unit and the metallacrown captures two Na(+) ions in the central cavity above and below the plane of the metallacrown. Each Na(+) ion is seven-coordinate and is bridged to two ring Mn(III) ions, through either a coordinating DMF mol-ecule or a chloro-acetate anion. The ring Mn(III) ions have either a tetra-gonally distorted octa-hedral geometry or a distorted square-pyramidal geometry. Weak C-H⋯O inter-actions, in addition to pure van der Waals forces, contribute to the overall packing of the mol-ecules. The complete molecule has inversion symmetry and is disordered over two sets of sites with an occupancy ratio of 0.8783 (7):0.1217 (7). The solvent molecule is also disordered over two sets of sites, with an occupancy ratio of 0.615 (5):0.385 (5).

µ3-Acetato-µ2-acetato-(di-methyl-form-amide)-penta-kis-(µ-N,2-dioxido-benzene-1-carboximidato)penta-kis-(1-methyl-1H-imidazole)-penta-manganese(III)manganese(II)-diethyl ether-di-methyl-formamide-methanol-water (1/1/1/1/0.49).

The title compound, [Mn6(C7H4NO3)5(CH3CO2)2(C4H6N2)4.62(C3H7NO)1.38]·(C2H5)2O·C3H7NO·CH3OH·0.49H2O or Mn(II)(OAc)2[15-MCMn(III)N(shi)-5](Me-Im)4.62(DMF)1.38·diethyl ether·DMF·MeOH·0.49H2O (where MC is metallacrown, (-)OAc is acetate, shi(3-) is salicyl-hydroximate, Me-Im is 1-methyl-imidazole, DMF is N,N-di-methyl-formamide, and MeOH is methanol), is comprised of five Mn(III) ions in the metallacrown ring and an Mn(II) ion which is encapsulated in the central cavity. Four of the ring Mn(III) ions are six-coordinate with distorted octa-hedral geometries. Two of these Mn(III) ions have a planar configuration, while the other two Mn(III) have Λ absolute stereoconfiguration. The fifth Mn(III) is five-coordinated with distorted square-pyramidal geometry. Four of the ring Mn(III) ions each bind one 1-methyl-imidazole, while the final ring Mn(III) ion binds a DMF solvent mol-ecule in an axial position and located in a trans position is either a Me-Im or a DMF mol-ecule. The occupancy ratio of Me-Im to DMF is 0.62 (2) to 0.38 (2). The central Mn(II) is seven-coordinate with a geometry best described as distorted face-capped trigonal-prismatic. DMF, diethyl ether, MeOH, and water mol-ecules are located in the inter-stitial voids between the metallacrown mol-ecules. The methanol mol-ecule is positionally disordered [0.51 (1):0.49 (1)] and associated with a partially occupied water mol-ecule [0.49 (1)]. This disorder is also associated with the positional disorder of the diethyl ether mol-ecule [0.51 (1):0.49 (1)].

Bis(di-methyl-formamide)-penta-kis-(µ-N,2-dioxido-benzene-1-carb-ox-imidato)tetra-kis-(1-methyl-imidazole)di-µ-propionato-penta-manganese(III)manganese(II)-di-methyl-formamide-methanol (1/0.24/1.36).

The title compound [Mn6(C7H4NO3)5(C3H5O2)2(C4H6N2)4.17(C3H7NO)1.83]·0.24C3H7NO·1.36CH3OH or Mn(II)(C3H5O2)2[15-MCMn(III)N(shi)-5](Me-Im)4.17(DMF)1.83·0.24DMF·1.36MeOH (where MC is metallacrown, shi(3-) is salicyl-hydroximate, Me-Im is 1-methyl-imidazole, DMF is N,N-di-methyl-formamide, and MeOH is methanol), contains an Mn(II) ion in the central cavity and five Mn(III) ions in the MC ring. The central Mn(II) ion is seven coordinate and has a geometry best described as distorted face-capped trigonal prismatic with Φ angles of 6.13, 10.36, and 11.73° and an estimated average s/h ratio of 1.03±0.11. Four of the ring Mn(III) ions are six coordinate with distorted octa-hedral geometries. Two of the Mn(III) ions have Λ absolute stereoconfiguration, while the other two Mn(III) ions have a planar configuration. The fifth Mn(III) ion is five coordinate and has a distorted square pyramidal geometry with τ = 0.20. Three of the Mn(III) ions bind one 1-methyl-imidazole ligand. Two of the ring Mn(III) ions have a 1-methyl-imidazole and a DMF disordered over a coordination site. For one of the ring Mn(III) ions, the occupancy ratio of the ligands refines to 0.51 (1):0.49 (1) in favor of the DMF. For the other ring Mn(III) ion, the occupancy ratio of the ligands refines to 0.68 (1):0.32 (1) in favor of the 1-methyl-imidazole. Two propionate anions serve to bridge the central Mn(II) ion between two different Mn(III) ions. The methyl groups of the bridging propionate anions are disordered over two positions. The methyl group disorder also induces disorder in the H atoms of the adjacent methyl-ene C atom to the same degree. For one of the propionate anions, the occupancy ratio refines to 0.752 (8):0.248 (8) and for the second, the occupancy ratio refines to 0.604 (6):0.396 (6). In addition, the disorder of the methyl group of the latter propionate anion is correlated with a partially occupied [0.604 (6)] methanol mol-ecule. Furthermore, a methanol mol-ecule and a DMF mol-ecule are positionally disordered in the lattice. The occupancy refines to 0.757 (7):0.243 (7) in favor of the methanol mol-ecule. Correlated to the occupancy of the methanol and DMF mol-ecules is a disordered benzene ring of one salicyl-hydroximate ligand. The benzene ring is disordered over two positions with an occupancy ratio of 0.757 (7):0.243 (7). Lastly, the two lattice methanol mol-ecules are hydrogen bonded to the 15-MC-5 mol-ecule. For the partially occupied methanol mol-ecule associated with the disordered propionate anion, the hydroxyl group of the methanol is hydrogen bonded to a carboxyl-ate O atom of the propionate anion. For the partially occupied methanol mol-ecule associated with the partially occupied lattice DMF mol-ecule, the hydroxyl group of the methanol is hydrogen bonded to the phenolate O atom of a salicyl-hydroximate ligand and to the carbonyl O atom of a coordinated DMF mol-ecule.

Penta-kis-(µ3-N,2-di-oxido-benzene-1-car-box-imid-ato)di-µ2-formato-penta-kis-(1H-imidazole)-methanolpenta-manganese(III)man-gan-ese(II)-methanol-water (1/3.36/0.65).

The title compound, [Mn6(C7H4NO3)5(CHO2)2(C3H4N2)5(CH3OH)]·3.36CH3OH·0.65H2O, or Mn(II)(O2CH)2[15-MCMn(III)N(shi)-5](Im)5(MeOH)·3.36MeOH·0.65H2O (where MC is metallacrown, shi(3-) is salicyl-hydroximate, Im is imidazole and MeOH is methanol), contains five Mn(III) ions as members of the metallacrown ring and an Mn(II) atom bound in the central cavity. The central Mn(II) atom is seven-coordinate with a geometry best described as between face-capped trigonal-prismatic and face-capped octa-hedral. Three Mn(III) ions of the metallacrown ring are six-coordinate with distorted octa-hedral geometries. Of these six-coordinate Mn(III) ions, two have mirror-plane configurations, while the other has a Δ absolute stereoconfiguration. The remaining two Mn(III) ions have a coordination number of five with a distorted square-pyramidal geometry. The five imidazole ligands are bound to five different Mn(III) ions. Disorder is observed for one of the coordinating imidazole ligands, as the imidazole ligand is disordered over two alternative mutually exclusive positions in a ratio of 0.672 (9) to 0.328 (9). The inter-stitial voids between the main mol-ecules that constitute the structure are mostly filled with methanol mol-ecules that form hydrogen-bonded chains. Some of the sites of the non-coordinated methanol mol-ecules are not fully occupied, with the remainder of the volume either empty or taken up by ill-defined close to amorphous content. One site was refined as being taken up by either two or one methanol mol-ecules, with an occupancy ratio of 0.628 (5) to 0.343 (5). This disorder might thus be correlated with the disorder of the imidazole ring (an N-H⋯O hydrogen bond between the major moieties of the imidazole and the methanol mol-ecules is observed). On the other side of the disordered imidazole ring the chain of partially occupied methanol mol-ecules originates that extends via O-H⋯O hydrogen bonds to the metal-coordinated methanol mol-ecule. The three partially occupied methanol mol-ecules were refined to be disordered with two water mol-ecules to take two residual electron density peaks into account (the exact nature of these weak residual electron density peaks cannot be deduced from the X-ray diffraction data alone, the assignment as water is tentative). The occupancy rate for the methanol mol-ecules refined to 0.480 (7). The occupancy rate of the two water mol-ecules refined to 0.34 (1) and 0.31 (2) for each site.

Di-µ-acetato-bis-(dimethyl-formamide)-penta-kis-(µ-N,2-dioxidobenzene-1-car-boximidato)tetra-kis-(1-ethyl-imidazole)-penta-manganese(III)-manganese(II)-diethyl ether-dimethyl-foramide-methanol-water (1/1/1/1/0.12).

The title compound [Mn(6)(C(7)H(4)NO(3))(5)(CH(3)CO(2))(2)(C(5)H(8)N(2))(4)(C(3)H(7)NO)(2)]·(C(2)H(5))(2)O·C(3)H(7)NO·CH(3)OH·0.12H(2)O, abbreviated as Mn(II)(OAc)(2)[15-MC(MnIII(N)shi)-5](EtIm)4(DMF)2·diethyl ether·DMF·MeOH·0.12H(2)O (where (-)OAc is acetate, MC is metallacrown, shi(3-) is salicylhydroximate, EtIM is n-ethylimidazole, DMF is N,N-dimethylformamide, and MeOH is methanol) contains five Mn(III) ions as members of the metallacrown ring and an Mn(II) ion bound in the central cavity. The central Mn(II) ion is seven-coordinate with a distorted face-capped trigonal-prismatic geometry. The five Mn(III) ions of the metallacrown ring are six-coordinate with distorted octa-hedral geometries. The configuration of the Mn(III) ions about the metallacrown ring follow a ΔΛΔPP pattern, with P representing planar. The four 1-ethyl-imidazole ligands are bound to four different Mn(III) ions. A diethyl ether solvent mol-ecule was found to be disordered over two mutually exclusive sites with an occupancy ratio of 0.568 (7):0.432 (7). A methanol solvent mol-ecule was found to be disordered over two mutually exclusive sites by being hydrogen bonded either to a dimethyl-formamide solvent mol-ecule (major occupancy component) or to an O atom of the main mol-ecule (minor occupancy component). The occupancy ratio refined to 0.678 (11):0.322 (11). Associated with the minor component is a partially occupied water mol-ecule [total occupancy 0.124 (15)].

Single molecule magnet behavior of a pentanuclear Mn-based metallacrown complex: solid state and solution magnetic studies.

The magnetic behavior of the pentanuclear complex of formula Mn(II)(O(2)CCH(3))(2)[12-MC(Mn(III)(N)shi)-4](DMF)(6), 1, was investigated using magnetization and magnetic susceptibility measurements both in the solid state and in solution. Complex 1 has a nearly planar structure, made of a central Mn(II) ion surrounded by four peripheral Mn(III) ions. Solid state variable-field dc magnetic susceptibility experiments demonstrate that 1 possesses a low value for the total spin in the ground state; fitting appropriate expressions to the data results in antiferromangetic coupling both between the peripheral Mn(III) ions (J = -6.3 cm(-1)) and between the central Mn(II) ion and the Mn(III) ones (J' = -4.2 cm(-1)). In order to obtain a reasonable fit, a relatively large single ion magnetic anisotropy (D) value of 1 cm(-1) was necessary for the central Mn(II) ion. The single crystal magnetization measurements using a microsquid array display a very slight opening of the hysteresis loop but only at a very low temperature (0.04 K), which is in line with the ac susceptibility data where a slow relaxation of the magnetization occurs just around 2 K. In frozen solution, complex 1 displays a frequency dependent ac magnetic susceptibility signal with an energy barrier to magnetization reorientation (E) and relaxation time at an infinite temperature (τ(o)) of 14.7 cm(-1) and 1.4 × 10(-7) s, respectively, demonstrating the single molecule magnetic behavior in solution.