Synthesis and crystal structure of 2-[(2,3,5,6-tetra-fluoro-pyridin-4-yl)amino]-ethyl methacrylate.

In the title compound, C11H10F4N2O2, the conformation about the N-C-C-O bond is gauche [torsion angle = 61.84 (13)°]. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into [010] chains, which are cross-linked by C-H⋯F and C-H⋯π contacts. Hirshfeld surface analysis was conducted to aid in the visualization of these various influences on the packing. This analysis showed that the largest contribution to the surface contacts arises from F⋯H/H⋯F inter-actions (35.6%), followed by O⋯H/H⋯O (17.8%) and H⋯H (12.7%).

Halogen, chalcogen, and hydrogen bonding in organoiodine cocrystals of heterocyclic thiones: imidazolidine-2-thione, 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole.

Through the combination of heterocyclic thiones with variation in the identity of the heterocyclic elements, namely, imidazolidine-2-thione, 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, 2-mercaptobenzoxazole, and 2-mercaptobenzothiazole with the common halogen-bond donors 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene, 1,3,5-trifluorotriiodobenzene, and tetraiodoethylene, a series of 18 new crystalline structures were characterized. In most cases, N-H...S hydrogen bonding was observed, with these interactions in imidazole-containing structures typically resulting in two-dimensional motifs (i.e. ribbons). Lacking the second N-H group, the thiazole and oxazole hydrogen bonding resulted in only dimeric pairs. C-I...S and C-I...I halogen bonding, as well as C=S...I chalcogen bonding, served to consolidate the packing by linking the hydrogen-bonding ribbons or dimeric pairs.

Metal-mediated rearrangement of 1,2-diphenylhydrazine to ortho-semidine upon reaction with dichlorotris(triphenylphosphine)ruthenium(II).

Reaction between RuCl2(PPh3)3 and 1,2-diphenylhydrazine resulted in rearrangement and coordination of ortho-semidine. The product, RuCl2(PPh3)2(κ2-NH2-1,2-C6H4-NHPh), was characterized spectroscopically and the molecular structure was conclusively determined using X-ray crystallography. Computational chemistry was employed to probe the energetics surrounding the rearrangement reaction and product.

The reaction of thiourea and 1,3-dimethylthiourea towards organoiodines: oxidative bond formation and halogen bonding.

By varying the halogen-bond-donor molecule, 11 new halogen-bonding cocrystals involving thiourea or 1,3-dimethylthiourea were obtained, namely, 1,3-dimethylthiourea-1,2-diiodo-3,4,5,6-tetrafluorobenzene (1/1), C6F4I2·C3H8N2S, 1, thiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene (1/1), C6F4I2·CH4N2S, 2, 1,3-dimethylthiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene (1/1), C6F4I2·C3H8N2S, 3, 1,3-dimethylthiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene-methanol (1/1/1), C6F4I2·C3H8N2S·CH4O, 4, 1,3-dimethylthiourea-1,3-diiodo-2,4,5,6-tetrafluorobenzene-ethanol (1/1/1), C6F4I2·C3H8N2S·C2H6O, 5, 1,3-dimethylthiourea-1,4-diiodo-2,3,5,6-tetrafluorobenzene (1/1), C6F4I2·C3H8N2S, 6, 1,3-dimethylthiourea-1,3,5-trifluoro-2,4,6-triiodobenzene (1/1), C6F3I3·C3H8N2S, 7, 1,3-dimethylthiourea-1,1,2,2-tetraiodoethene (1/1), C6H16N4S2·C2I4, 8, [(dimethylamino)methylidene](1,2,2-triiodoethenyl)sulfonium iodide-1,1,2,2-tetraiodoethene-acetone (1/1/1), C5H8I3N2S+·I-·C3H6O·C2I4, 9, 2-amino-4-methyl-1,3-thiazol-3-ium iodide-1,1,2,2-tetraiodoethene (2/3), 2C4H7N2S+·2I-·3C2I4, 10, and 4,4-dimethyl-4H-1,3,5-thiadiazine-3,5-diium diiodide-1,1,2,2-tetraiodoethene (2/3), 2C5H12N4S2+·4I-·3C2I4, 11. When utilizing the common halogen-bond-donor molecules 1,2-, 1,3-, and 1,4-diiodotetrafluorobenzene, as well as 1,3,5-trifluoro-2,4,6-triiodobenzene, bifurcated I...S...I interactions were observed, resulting in the formation of isolated rings, chains, and sheets. Tetraiodoethylene (TIE) provided I...S...I cocrystals as well, but further yielded a sulfonium-containing product through the reaction of the S atom with TIE. This particular sulfonium motif is the first of its kind to be structurally characterized, and is stabilized in the solid state through a three-dimensional I...I halogen-bonding network. Thiourea reacted with acetone in the presence of TIE to provide two novel heterocyclic products, again stabilized in the solid state through I...I halogen bonding.

Halogen Bonding in Dithiane/Iodofluorobenzene Mixtures: A New Class of Hydrophobic Deep Eutectic Solvents.

While research into deep eutectic solvents (DESs) has expanded over the previous two decades, the focus has remained on the utilization of hydrogen bond donors in these systems. Additionally, the majority of the known DESs rely on at least one ionic component. Through the combination of 1,3-dithiane and 1,2-diiodo-3,4,5,6-tetrafluorobenzene (1,2-F4 DIB), we report the first known DES based on halogen bonding. This mixture remains a liquid, with a eutectic melting temperature of 13.7 °C over a range of 1,3-dithiane mole fraction (0.35 to 0.75). Additionally, cocrystals of 1,3- and 1,4-dithiane with 1,2-, 1,3-, and 1,4-F4 DIB, as well as 1,3,5-trifluoro-2,4,6-triiodobenzene were studied via single-crystal X-ray diffraction. These data reveal a wide range of halogen bonding strengths (0.85

Polymorphism, Halogen Bonding, and Chalcogen Bonding in the Diiodine Adducts of 1,3- and 1,4-Dithiane.

Through variations in reaction solvent and stoichiometry, a series of S-diiodine adducts of 1,3- and 1,4-dithiane were isolated by direct reaction of the dithianes with molecular diiodine in solution. In the case of 1,3-dithiane, variations in reaction solvent yielded both the equatorial and the axial isomers of S-diiodo-1,3-dithiane, and their solution thermodynamics were further studied via DFT. Additionally, S,S'-bis(diiodo)-1,3-dithiane was also isolated. The 1:1 cocrystal, (1,4-dithiane)·(I2) was further isolated, as well as a new polymorph of S,S'-bis(diiodo)-1,4-dithiane. Each structure showed significant S···I halogen and chalcogen bonding interactions. Further, the product of the diiodine-promoted oxidative addition of acetone to 1,4-dithiane, as well as two new cocrystals of 1,4-dithiane-1,4-dioxide involving hydronium, bromide, and tribromide ions, was isolated.

Halogen and Chalcogen Bonding Between the Triphenylphosphine Chalcogenides (Ph3 P=E; E=O, S, Se) and Iodofluorobenzenes.

A series of cocrystals of Ph3 P=E (E=O, S, Se) with organoiodines were studied to understand the roles of noncovalent interactions including chalcogen (ChB) and halogen (XB) bonding in their formation. The structure of the cocrystal of Ph3 P=S and 1,2-diiodotetrafluorobezene was determined, which demonstrates a similar chalcogen⋅⋅⋅iodine XB pattern to the previously reported isomorphic Ph3 P=Se structure. The cocrystalline structures resulting from the combination of 1,3-diiodotetrafluorobenzene (1,3-F4 DIB), as well as iodopentafluorobenzene, with all three triphenylphosphine chalcogenides, were also determined. The (Ph3 P=Se) ⋅ (1,3-F4 DIB) cocrystal presents a rare example of a selenium⋅⋅⋅organoiodine ChB. The observed ChB and XB interactions have normalized distance parameters (RXB ) ranging from 0.80 to 0.98. The strength of the XB and ChB interactions were analyzed using natural bond orbital (NBO) theory, with calculated energies falling between 3.14 kcal/mol and 12.81 kcal/mol.

Crystal Engineering Using Polyiodide Halogen and Chalcogen Bonding to Isolate the Phenothiazinium Radical Cation and Its Rare Dimer, 10-(3-Phenothiazinylidene)phenothiazinium.

Utilizing facile one-electron oxidation of 10H-phenothiazine by molecular diiodine, the solid-state structure of the 10H-phenothiazinium radical cation was obtained in three cation:iodide ratios, as well as its THF and acetone solvates. Oxidation of 10H-phenothiazine with molecular diiodine in DMSO or DMF provided the structure of the radical coupling product 10-(3-phenothiazinyldene)phenothiazinium, which has not been crystallographically characterized to date. The radical cations were balanced by a mixture (I7 )- , (I5 )- , (I3 )- , and I- anions, where a variety of chalcogen, halogen, and hydrogen bonding interactions stabilize the structures to reveal these interesting cationic species.

Halogen Bonding of Organoiodines and Triiodide Anions in (NMe3 Ph)+ Salts.

To study the role of the triiodide (I3 )- anion in establishing various halogen bonding patterns, the trimethylphenylammonium iodide (NMe3 PhI) salt was reacted with diiodine (I2 ) in the presence of a series of organoiodines, tetraiodoethylene (TIE), 1,2-diiodo-3,4,5,6-tetrafluorobenzene (o-F4 DIB), 1,4-diiodo-2,3,5,6-tetrafluorobenzene (p-F4 DIB), and 1,3,5-trifluoro-2,4,6-triiodobenzene (1,3,5-F3 I3 B) to form cocrystals of the organoiodines with the trimethylphenylammonium triiodide (NMe3 PhI3 ) salt. Single-crystal X-ray crystallography revealed the (I3 )- anion served as a halogen bond acceptor for the organoiodine donors, forming a variety of 1-D, 2-D, and 3-D packing arrangements through I⋅⋅⋅I halogen bonding. Significant asymmetry was observed within the (I3 )- anion. The melting points of the cocrystalline materials, as determined by simultaneous DSC/TGA, ranged from 43 °C to 119 °C and showed a strong dependence on the identity of the organoiodine incorporated into the crystal lattice.

Correlation of Structure with Crystalline to Amorphous Phase Transitions of 1,3,6-Substituted Fulvene-Derived Molecular Glasses.

An investigation into the crystalline to amorphous phase transitions of prepared 1,3,6-substituted pentafulvenes showed the expected reversible heated melt and cooling recrystallization in only a few examples. Systematic incorporation of bulky substituents at the 6-position of the fulvene ring led to the nonreversible thermal behavior, rendering phases that were locked into glassy, vitrified states. These molecular glasses produced physically translucent and amorphous features with glass transition temperatures in the range of 61-77 °C, comparable with high-strength plastics such as polyethylene terephthalate. Additionally, the melting point transitions and the resulting heat of fusion values were found to be directly influenced by the nature of the 6-position substituent. Single crystal X-ray crystallography showed that in some cases, fulvenes possessing fused aromatics exhibited a high degree of intermolecular π-π stacking. These results point to a class of molecular glass formers as host materials possessing tunable bulk properties for potentially new optical applications.

Single-crystal X-ray diffraction dataset for 3,5-difluoro-2,6-bis(4-iodophenoxy)-4-phenoxypyridine.

The data in this article are related to the research article "Utilizing the Regioselectivity of Perfluoropyridine towards the Preparation of Phenyoxyacetylene Precursors for Partially Fluorinated Polymers of Diverse Architecture."1 The X-ray structure analysis of 3,5-difluoro-2,6-bis(4-iodophenoxy)-4-phenoxypyridine has revealed an asymmetric unit containing two molecules, linked via both Type I and Type II C-I∙∙∙I-C halogen bonding interactions. The packing is further consolidated via Ar-H∙∙∙π interactions. This compound has been utilized for the synthesis of monomers for linear and network polymers.

Crystal structures of a series of 6-aryl-1,3-diphenyl-fulvenes.

The synthesis and crystal structures of a series of 6-aryl-fuvlenes (fulvene is 5-methyl-idene-cyclo-penta-1,3-diene) with varying methyl-ation patterns on the 6-phenyl substituent are reported, namely 6-(3-methyl-phen-yl)-1,3-di-phenyl-fulvene (C25H20), 6-(4-methyl-phen-yl)-1,3-di-phenyl-fulvene (C25H20), 6-mesityl-3-di-phenyl-fulvene (C27H24) and 6-(2,3,4,5,6-penta-methyl-phen-yl)-1,3-di-phenyl-fulvene (C29H28). The bond lengths are typical of those observed in related fulvenes. A network of C-H⋯π ring inter-actions consolidates the packing in each structure.

Crystal structures and Hirshfeld surface analysis of a series of 4-O-aryl-perfluoro-pyridines.

Five new crystal structures of perfluoro-pyridine substituted in the 4-position with phen-oxy, 4-bromo-phen-oxy, naphthalen-2-yl-oxy, 6-bromo-naphthalen-2-yl-oxy, and 4,4'-biphen-oxy are reported, viz. 2,3,5,6-tetra-fluoro-4-phen-oxy-pyridine, C11H5F4NO (I), 4-(4-bromo-phen-oxy)-2,3,5,6-tetra-fluoro-pyridine, C11H4BrF4NO (II), 2,3,5,6-tetra-fluoro-4-[(naphthalen-2-yl)-oxy]pyridine, C15H7F4NO (III), 4-[(6-bromo-naphthalen-2-yl)-oxy]-2,3,5,6-tetra-fluoropyridine, C15H6BrF4NO (IV), and 2,2'-bis-[(perfluoro-pyridin-4-yl)-oxy]-1,1'-biphenyl, C22H8F8N2O2 (V). The dihedral angles between the aromatic ring systems in I-IV are 78.74 (8), 56.35 (8), 74.30 (7), and 64.34 (19)°, respectively. The complete mol-ecule of V is generated by a crystallographic twofold axis: the dihedral angle between the pyridine ring and adjacent phenyl ring is 80.89 (5)° and the equivalent angle between the biphenyl rings is 27.30 (5)°. In each crystal, the packing is driven by C-H⋯F inter-actions, along with a variety of C-F⋯π, C-H⋯π, C-Br⋯N, C-H⋯N, and C-Br⋯π contacts. Hirshfeld surface analysis was conducted to aid in the visualization of these various influences on the packing.

Syntheses, crystal structures and Hirshfeld surface analyses of (3aR,4S,7R,7aS)-2-(perfluoro-pyridin-4-yl)-3a,4,7,7a-tetra-hydro-4,7-methano-iso-indole-1,3-dione and (3aR,4S,7R,7aS)-2-[(perfluoro-pyridin-4-yl)-oxy]-3a,4,7,7a-tetra-hydro-4,7-methano-iso-indole-1,3-dione.

The syntheses and crystal structures of the title compounds, C14H8F4N2O2 and C14H8F4N2O3, are reported. In each crystal, the packing is driven by C-H⋯F inter-tactions, along with a variety of C-H⋯O, C-O⋯π, and C-F⋯π contacts. Hirshfeld surface analysis was conducted to aid in the visualization of these various influences on the packing: they showed that the largest contributions to the surface contacts arise from H⋯F/F⋯H inter-actions, followed by H⋯H and O⋯H/H⋯O.

Coordination complexes of chromium(0) with a series of 1,3-diphenyl-6-aryl-fulvenes.

The synthesis and structural properties of a series of chromium tricarbonyl 'piano-stool' complexes bearing substituted penta-fulvene ligands were studied. The complexes, tricarbon-yl(1,3,6-tri-phenyl-fulvene)chromium(0) benz-ene hemisolvate, [Cr(C24H18)(CO)3]·0.5C6H6 (I), tricarbon-yl[1,3-di-phen-yl-6-(3-vinyl-phen-yl)fulvene]chromium(0), [Cr(C26H20)(CO)3] (II), and tricarbon-yl[1,3-diphenyl-6-(pyren-1-yl)fulvene]chromium(0), [Cr(C34H22)(CO)3] (III), each have a distorted octa-hedral geometry, with the fulvene coordinated in a π-η2:π-η2:π-η2 fashion. Significant deviation of the exocyclic fulvene double bond from the cyclo-penta-diene plane accompanies coordination. Evidence of non-covalent π-π inter-actions was observed in both (I) and (III), with centroid-to-centroid distances ranging from 3.330 (8) to 3.494 (8) Å.

Crystal structure of chlorido-(dimethyl sulfoxide-κS)bis-[4-(pyridin-2-yl)benzaldehyde-κ3C2,N]iridium(III) aceto-nitrile monosolvate.

The title compound, [IrCl(C12H8NO)2{(CH3)2SO}]·H3CCN or [IrCl(fppy)2(DMSO)]·H3CCN [where fppy is 4-(pyridin-2-yl)benzaldehyde and DMSO is dimethyl sulfoxide], is a mononuclear iridium(III) complex including two fppy ligands, a sulfur-coordinating DMSO ligand, and one terminal chloride ligand that define a distorted octa-hedral coordination sphere. The complex crystallizes from 1:1 DMSO-aceto-nitrile as an aceto-nitrile solvate. In the crystal, weak C-H⋯O and C-H⋯N hydrogen-bonding inter-actions between adjacent complexes and between the aceto-nitrile solvent and the complex consolidate the packing.

Synthesis of 1,3-diphenyl-6-alkyl/aryl-substituted fulvene chromophores: observation of π-π interactions in a 6-pyrene-substituted 1,3-diphenylfulvene.

The synthesis, structural, and electronic properties of nine 1,3-diphenyl-6-alkyl/aryl substituted pentafulvenes were studied. Pyrene ring π-π interactions were revealed from analysis of the experimental crystal packing of 1,3-diphenyl-6-(1-pyrene)fulvene and supporting DFT calculations. Photophysical properties derived from UV-vis and fluorescence emission measurements demonstrated tunable and low HOMO-LUMO band gaps for the series. The presented results point to a model synthetic approach for incorporation of extended π systems and donor-π-acceptor groups for fulvene-based electronic materials.

NCN trianionic pincer ligand precursors: synthesis of bimetallic, chelating diamide, and pincer group IV complexes.

This report details the synthesis of new NCN trianionic pincer ligand precursors and metalation reactions to form group (IV) complexes. N,N'-[1,3-phenylenebis(methylene)]bis-2,6-diisopropylaniline [2,6-(i)PrNCN]H(3) (8) was converted to the N,N'-substituted Si(IV), Sn(IV), Mg(II), and Zn(II) derivatives. [2,6-(i)PrNCHN](SiMe(3))(2) (9-Si) and [2,6-(i)PrNCHN](SnMe(3))(2) (9-Sn) form by first treating 8 with MeLi followed by Me(3)MCl, where M = Si or Sn. Single crystal X-ray experiments indicate 8, 9-Si, and 9-Sn have similar structural features in the solid state. [2,6-(i)PrNCHN](mu-MgCl.THF)(2) (12) forms by treating 8 with MeMgCl, and its solid state structure revealed a bis-mu-MgCl bridging unit. The (1)H NMR spectrum of 12 reveals a dynamic process occurs in solution. A variable temperature (1)H NMR experiment failed to quench the dynamic process. {[2,6-(i)PrNCHN]Zn}(2) (13) forms upon treating {[2,6-(i)PrNCHN]Li(2)}(2) (10) with anhydrous ZnCl(2) and is a dimer in the solid state. Again, dynamic (1)H NMR behavior is observed, and a mechanism is provided to explain the apparent low symmetry of 13 in solution. Extension of the aliphatic arm of the NCN ligand provides the new N(C)C(C)N pincer ligand precursors N,N'-(2,2'-(1,3-phenylene)bis(ethane-2,1-diyl))bis(3,5-bis(trifluoromethyl)aniline) [3,5-CF(3)N(C)C(C)N]H(3) (16) and [3,5-CF(3)N(C)CH(C)N](SiMe(3))(2) (17). A more rigid ligand architecture was accessed by synthesis of the anthracene derived pincer ligand anthracene-1,8-diylbis(N-3,5-bistrifluormethylaniline) [3,5-CF(3)N(C)C(anth)(C)N]H(3) (18). Treating {Zr(NMe(2))(4)}(2) with 2 equiv of 16 provides the dimer {(mu-3,5-CF(3)N(C)CH(C)N)Zr(NMe(2))(3)NHMe(2)}(2) (19). Treating Hf(NMe(2))(4) with 18 provides the bimetallic complex (mu-3,5-CF(3)N(C)CH(anth)(C)N){Hf(NMe(2))(3)NHMe(2)}(2) (20) in which one ligand bridges two Hf(IV) ions. Salt metathesis between 10 and ZrCl(2)(NMe(2))(2)(THF)(2) provides the mononuclear complex [2,6-(i)PrNCHN]Zr(NMe(2))(2) (21) in which the NCN ligand is bound as a chelating diamide. Thermoysis of 21 does not lead to formation of a trianionic pincer complex. Instead, treating HfCl(4) with {[2,6-(i)PrNCN]Li(3)}(2) (11) followed by MeLi provides the trianionic pincerate complex [2,6-(i)PrNCNHfMe(2)][Li(DME)(2)] (23). In the solid state the Hf ion has distorted trigonal bipyramidal geometry.