Coordination polymers organotin

By appropriate choice of the reactants and the reaction conditions, a phenol-substituted carboxylic acid may react with an organotin compound to give both an organotin ester and an organotin aryl oxide within the same molecule. The reaction of trimethyltin chloride with 4-hydroxy-3-methoxybenzoic acid (HVAH) in the presence of water and pyridine at 130 °C in a sealed tube gave the unique two-dimensional coordination polymer 134 (equation 2)286. 

Aik X = Cl, Br, I) were described. This series can be supplemented with the Me2SnO Me2Sn(OH)I adduct. Such complexes often appeared as by-products when the syntheses of organotin compounds having a Sn—X or Sn—O bond were carried out. It is noteworthy that many solid organotin compounds having the stannoxane bond were found to be coordinated polymers rather than monomers, as hitherto considered, because their molecules were bonded by donor-acceptor (bridge) Sn—O Sn bonds. ... 

Considering that the formation of metallocyclic polygons and polyhedra requires at least two free coordination sites, the number of possible bonding environments is limited. Figure 2.5.2 summarizes the coordination geometries found most frequently in organotin(IV) macrocycles and coordination polymers. 

Next, the possible existence of coordination polymers in solution was investigated (43). The viscosity of solutions of iV-tributylstannylimidazole and iV-tributylstannyl-1,2,4-triazole in toluene was found to be highly dependent on concentration. No viscosity increase was found, however, for iV-tributylstannylpyrrole and -pyrazole. Obviously, a coordination polymer is present in not too dilute solutions (>0.5% or about 0.01 M) of the former organotin derivatives (Fig. 2). 

Of great importance for both the formation and photochemical cross-linked of organotin oligomers and polymers is the tin atom in the coordination-bound state. 

The structural chemistry of the organotin halides is dominated by their Lewis acid properties and their propensity to form five- and six-coordinate complexes. Self-association may give oligomers or polymers in the solid state, which usually dissociate in solution. The structure of tricyclohexyltin chloride in the crystal is temperature-dependent. At 108 K, it has the form of a rod-like polymer with distorted trigonal-bipyramidal tin and Sn-Cl separations of 245.6(7) and 300.77(7) pm, but at 298 K, the structure is best regarded as consisting of near-tetrahedral discrete molecules.3... 

Few X-ray diffraction data are available for the organotin alkoxides. Trimethyltin methoxide in the crystal is a five-coordinate linear polymer 47,380 and both tin atoms in the methanol solvate, CH2(SnPh2OMe)2-MeOH, are five coordinate, one by intramolecular coordination, and the other by solvation 48.381 Dimethyltin dimethoxide 49,382 dimethyltin diphenoxide 50,383 and isopropyltin triisopropoxide 51384 are five-coordinate oxygen-bridged dimers. All these compounds are monomers in solution. 

Polycondensates with the Ligand as a Comonomer. Metal-bearing polycondensates in which the ligand moiety alone or in combination with the coordinated metal ions form one of the backbone comonomers are exemplified by the following polymers reported by Wudl et al [48], Biswas and Mazumdar [49, 50] and by Takahashi et al. [51] in the synthesis of organotin polymer by a similar condensate (Figs. 20, 21). 

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