Adducts of meso and racemic 5,5,7,12,12,14-hexamethyl-1,4,8, 11-tetraazacyclotetradecane with trigonally trisubstituted benzene carboxylic acids: supramolecular structures in one and two dimensions

The meso and racemic forms of 5,5,7,12,12,14-hexamethyl-1,4,8, 11-tetraazacyclotetradecane, C(16)H(36)N(4) (tet-a and tet-b, respectively), form adducts with trigonally trisubstituted benzene carboxylic acids; tet-a-3,5-dinitrobenzoic acid (1/2) (1), tet-a-5-hydroxyisophthalic acid-water (1/1/1) (3) and tet-b-5-hydroxyisophthalic acid-water (1/1/1) (4) are all salts, [C(16)H(38)N(4)](2+).2[C(7)H(3)N(2)O(6)](-) (1) and [C(16)H(38)N(4)](2+).[C(8)H(4)O(5)](2-).H(2)O (3) and (4). The conformations of the [(tet-a)H(2)](2+) and [(tet-b)H(2)](2+) cations are entirely different: [(tet-a)H(2)](2+) is precisely centrosymmetric in (1) and approximately so in (3), while [(tet-b)H(2)](2+) has approximate C(2) symmetry in (4). In each salt the cation forms two intramolecular N-H.N and four intermolecular N-H.O hydrogen bonds. In (1) the supramolecular structure is one-dimensional, a C(2)(2)(13)[R(2)(4)(16)] chain of rings. Compounds (3) and (4) crystallize in space groups P2(1)2(1)2(1) and P2(1)/c, respectively, but the supramolecular structures are very similar: in each, the anions and the water molecules form a C(7)[R(3)(3)(13)] chain of rings, generated in (3) by a 2(1) axis and in (4) by a glide plane. These chains are linked, in both (3) and (4), by cations to form sheets. Adjacent meso cations in (3) are related by a 2(1) axis and adjacent chiral cations in (4) are related by a glide plane.

Threefold interweaving of (4,4) nets built from R(10)10(58) rings inthe hydrogen-bonded adduct 1,4-diazabicyclo

The 1:1 adduct of 1,4-diazabicyclo[2.2.2]octane and 5-hydroxyisophthalic acid is a salt, [H(C(6)H(12)N(2))](+). [HOC(6)H(3)(COOH)COO](-) or C(6)H(13)N(2)(+).C(8)H(5)O(5)(-). The ions are linked by three types of hydrogen bond, i.e. N-H.O, O-H.O and O-H.N, into continuous two-dimensional (4,4) nets built from a single type of R(10)(10)(58) ring. Six independent sheets of this type make up the structure and these are interwoven in sets of three.

Selective ring-opening reactions of

The reactivity of strained [1]ferrocenophanes, [Fe(eta-C5H4)2ERx] (ERx = SiMe2, 1a: SiMePh, 1b; SnR2, 1c), towards boron halides has been investigated and has been shown to provide a facile pathway to ferrocene derivatives functionalized with Lewis acidic boron centers. The boron halides RBX2 (R = Cl, Ph, fc; X = Cl, Br) (fc = Fe(eta-C5H4)2) lead to selective cleavage of the Si-Cp bonds in 1a and 1b to give, depending on the reaction stoichiometry, functionalized mono- or diferrocenylboranes RnB [(eta-C5H4)Fe(eta-C5H4SiMe2Cl)](3-n) (2a: R = Cl, n = 2; 2b: R = Cl, n = 1; 2c: R = Ph, n = 1) and RnB[(eta-C5H4)Fe(eta-C5H4SiMePhCl)](3-n) (2d: R = Cl, n = 2) in high yields. Compounds 2a-d were characterized by multinuclear NMR spectroscopy, mass spectrometry, and by single-crystal X-ray diffraction (for 2b). Most likely due to steric constraints, a triferrocenylborane was not obtained even from the reaction of BCl3 with an excess of 1a, whereas facile formation of the diferrocenylphenylborane 2c from PhBCl2 and two equivalents of 1a was observed. Selective hydrolysis of the B-Cl bonds of chlorodiferrocenylborane 2b in the presence of trace amounts of water led to the silylated tetranuclear ferrocene complex [(ClMe2Sifc)2B-O-B(fcSiMe2Cl)2] (3) without cleavage of the Si-Cl bonds. The structure of 3 was confirmed by an X-ray diffraction study. Studies of the reactivity of the higher Group 14 homologue of 1a and 1b, the tin-bridged [1]ferrocenophane 1c, revealed that facile addition of B-Cl bonds occurs across the Sn-Cp bonds to yield the 1-stannyl-1'-borylferrocenes [(ClMes2Sn)fc(BClR)] (4a: R = Cl; 4b: R = Ph; Mes = 2,4,6-Me3C6H2). The new synthetic methodology can be extended to bifunctional Lewis acids such as the bis(boryl)ferrocene 1,1'-fc(BBr2)2, which affords the linear boron-bridged ferrocene trimer 1,1'-[fc[B(Br)fcSiMe2Br]2] 5 in 54% isolated yield. In order to incorporate the functionalized ferrocenylboranes into polymer structures, compound 2c was reduced with Li[BEt3H] to give the silicon-hydride functionalized species [PhB[(eta-C5H4)Fe(eta-C5H4SiMe2H)]2] (6), which was then used as a capping reagent in the transition metal catalyzed polymerization of 1a. This process leads to the incorporation of the ferrocenylborane unit into the main chain of a poly(ferrocenylsilane) to afford [PhB-[(fcSiMe2)(n-1)fcSiMe2H]2] (7).

Hydrogen-bonding behaviour of benzene-1,2,4,5-tetracarboxylic acid: supramolecular structures of different dimensionality in the 2:1 adducts formed with 4,4'-bipyridyl and hexamethylenetetramine

Co-crystallization of benzene-1,2,4,5-tetracarboxylic acid, C10H6O8, with 4,4'-bipyridyl, C10H8N2, or with hexamethylenetetramine, C6H12N4, from methanol solutions yields in each case a 2:1 salt, [(C10H9N2)+]2.[(C10H4O8)2-] (1) and [(C6H13N4)+]2.[(C10H4O8)2-] (2). In (1) the carboxylate anions lie across centres of inversion, but they contain no intramolecular O-H...O hydrogen bonds: the cations and anions are linked by strong O-H...N and N-H...O hydrogen bonds into a chain-of-rings, and these chains are further linked into a three-dimensional framework structure by means of C-H...O hydrogen bonds and aromatic pi...pi stacking interactions. Compound (2) contains two independent three-molecule aggregates, comprising a central anion and two cations, linked to the anion by means of short N-H...O hydrogen bonds. One of these aggregates is centrosymmetric, but the other is not, and the two types of anion both form two intramolecular O-H...O hydrogen bonds. The two types of three-molecule aggregate, in which all the anions are virtually parallel, are linked by short C-H...O hydrogen bonds into a molecular staircase.

3,6,9,16,19,22-Hexaazatricyclo

The adduct (1) formed between the hexaaza macrocycle 3,6,9,16,19,22-hexaazatricyclo[22.2.2.2(11,14]triconta-1(26),11(29),12,14(30),24,27-hexaene, C24H38N6, and 4,4'-sulfonyldiphenol, O2S(C6H4OH)2, is a salt [(C24H40N6)2+].2[(HOC6H4SO2C6H4O)-], and the adduct (2) formed by the same macrocyclic amine with 4,4'-biphenol is an aquated salt which also contains neutral biphenol molecules, [(C24H40N6)2+]. 2[(HOC6H4C6H4O)-].(HOC6H4C6H4OH).2H2O. In both compounds the cations lie across centres of inversion: there are two crystallographically distinct cation sites in (1) and the conformations of the cations occupying them are quite different. In (2) the single type of cation site is occupied by a conformationally disordered cation: the major and minor components represent two further distinct conformers. In (1) the anions are linked by O-H...O hydrogen bonds into chains, and each cation is linked by a total of six N-H...O hydrogen bonds to anions in four different chains, so linking the chains into continuous sheets. In (2) the anions and the water molecules are linked into sheets, which are further linked into a continuous three-dimensional framework by both the cations and the neutral biphenol units.

meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane as a building block in supramolecular chemistry; salts formed with 2,2-biphenol, 4,4-thiodiphenol, 4,4-sulfonyldiphenol, 3-and 4-hydroxybenzoic acids, 3,5-dihydroxybenzoic acid and phenylphosphonic acid; supramolecular structures in zero, one, two and three dimensions

The structure of meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-2,2'-biphenol (1/2), (C16H36N4).(C12H10O2)2 (1), is a salt [C16H38N4]2+.2[HOC6H4C6H4O]-: the cations are centrosymmetric with two protons held within the N4 cavity of the macrocycle by N-H...N hydrogen bonds, and the phenolate anions contain intramolecular O-H...O-hydrogen bonds. The ions are linked into a finite centrosymmetric aggregate by means of N-H...O hydrogen bonds. meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane-4,4'-thiobiphenol-methanol (1/2/2), (C16H36N4).(C12H10O2S)2.(CH4O)2 (2), and meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-4,4'-sulfonylbiphenol-methanol (1/2/2), (C16H36N4).(C12H10O4S)2.(CH4O)2 (3), are isomorphous: each is a salt, [C16H38N4]2+.2[HOC6H4SC6H4O]-.2MeOH (2) and [C16H38N4]2+.2[HOC6H4SO2C6H4O]-.2MeOH (3), and in each the phenolate anions are linked by O-H...O- hydrogen bonds into chains; antiparallel pairs of chains are cross-linked by the cations to form molecular ladders, with neutral methanol molecules acting as spacer units. In meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-3-hydroxybenzoic acid-methanol (1/2/2) (4), 3-hydroxybenzoate anions form chains, again cross-linked in pairs by the [C16H38N4]2+ cations to form molecular ladders, different from those in (2) and (3) in that the neutral methanol units are pendent from the ladders, rather than forming a part of it. meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane-4-hydroxybenzoic acid-methanol (1/2/1) (5) is again a salt, [C16H38N4]2+.2[HOC6H4COO]-.MeOH: chains of 4-hydroxybenzoate anions are continuously cross-linked by two different types of [C16H38N4]2+ cation into a two-dimensional net. Only one of the two types of cation is linked to the chains via neutral methanol spacer units. meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclotetradecane-phenylphosphonic acid-water (1/4/2) (6) is a salt, [C16H40N4]4+.4[C6H5PO3H]-.2H2O, containing the centrosymmetric tetraprotonated amine units, which have a conformation quite different from the trans-III conformation uniformly found in the [C16H38N4]2+ cations. The phenylphosphonate anions and the water molecules are linked into chains of fused rings, which are linked by the cations into two-dimensional nets. In meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetrade cane-3,5-dihydroxybenzoic acid (1/2) (7), the 3,5-dihydroxybenzoate anions in the unsolvated salt [C16H38N4]2+.2[(HO)2C6H3COO]- are linked into continuous two-dimensional nets, which are in turn linked by the centrosymmetric cations to form a three-dimensional framework. meso-5,5,7,12,12,14-Hexamethyl-1,4,8,11-tetraazacyclo tetradecane-4,4'-biphenol (1/3) (8) is a salt containing both neutral and anionic biphenol units, [C16H38N4]2+.2[HOC6H4-C6H4O]-.[HOC6H4C6H4OH]. The two types of biphenol unit form two-dimensional nets and these nets are linked by the cations to form three independent, three-dimensional frameworks which are fully interwoven, but not bonded to one another.

Two different three-dimensional hydrogen-bonded framework structures in two hydrated adducts meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane--terephthalic acid--water (1/1/4) and (1/1/6)

Co-crystallization of meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, C16H36N4, with terephthalic acid (1,4-benzenedicarboxylic acid), C8H6O4, from ethanol yields the tetrahydrate (C16H36N4).(C8H6O4).(H2O)4 (1), meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecaneterephthalic acid-water (1/1/4), while similar co-crystallization from methanol yields the hexahydrate (C16H36N4).(C8H6O4).(H2O)6 (2), meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-terephthalic acid-water (1/1/6). Both compounds are salts, [C16H38N4]2+.[C8H4O4]2-. 4H2O (1) and [C16H38N4]2+.[C8H4O4]2-.6H2O (2): in (2) both ionic components lie across centres of inversion and in both salts there are two protons held within the N4 cavity of the cation. In the structure of (1), the cations and anions are linked into chains by means of paired N-H...O hydrogen bonds, and the water molecules are linked into continuous chains by means of O--H...O hydrogen bonds, in which each of the H atoms is independently disordered over two equally populated sites. The water chains link the ionic chains into a continuous three-dimensional framework by means of further O-H...O hydrogen bonds. In (2) the cations and anions are linked by single N--H...O hydrogen bonds, again into chains: at the same time the anions and the water molecules are linked by multiple O-H...O hydrogen bonds into continuous two-dimensional nets, which are linked by the cations, by means of N--H...O hydrogen bonds into a three-dimensional framework, entirely different from that in (1).

Rhodium-Catalyzed Formation of Phosphorus-Boron Bonds: Synthesis of the First High Molecular Weight Poly(phosphinoborane).

An inorganic analogue of polystyrene, poly(phenylphosphinoborane) represents the first high molecular weight, well-characterized polymer with a backbone of alternating phosphorus and boron atoms. It is accessible by metal-catalyzed "dehydrocoupling" of a primary phosphane-borane adduct (see scheme).