Steric Control over Molecular Structure and Supramolecular Association Exerted by Tin- and Ligand-Bound Groups in Diorganotin Carboxylates

Abstract

Structural data (X-ray and solution and solid-state 119 Sn NMR) show that skew-trapezoidalbipyramidal diorganotin compounds of 2-quinaldate are invariably monomeric, owing to the steric bulk of the carboxylate ligand. In contrast, most of the analogous compounds of 2-picolinate (2-pic) can increase their coordination number by polymerization or the incorporation of solvent in their coordination sphere in the solid state. The exceptional compound is tBu 2 Sn(2-pic) 2 (3), for which no increase in coordination number is apparent, a result that is correlated with the bulky tert-butyl groups. Thus, judicious choice of tin or ligand substituents can be exploited to dictate coordination number and/or the degree of supramolecular aggregation in the investigated systems.

Polymeric topologies in cadmium(II) dithiophosphate adducts of the isomeric n-pyridinealdazines, n = 2, 3 and 4

“…In organotin systems, e.g. R 2 Sn(O 2 CR 0 ) 2 , where HO 2 CR 0 is 2-picolinic acid or 2-quinaldic acid, bulky tin-bound R groups have been shown to restrict polymerisation [11]; a similar situation pertains in the organomercury dithiolates [12]. In adduct formation with diimine bases, such as in systems of the general formula, [Zn(S 2 P(OR) 2 ) 2 (bridging dipyridyl-type ligand)] n [13][14][15], polymers can be precluded when the diimine base is too small to allow bridging.…”

Exploring the Topological Landscape Exhibited by Binary Zinc-triad 1,1-dithiolates

“…In short, the bulkier the R substituent, the less likely it is that supramolecular aggregation will occur. This concept is now well established in the structural chemistry of main group element 1,1-dithiolates [17,[40][41][42] and in the structural chemistry of related organotin carboxylates [43][44][45], where bulky groups can disrupt [18,[46][47][48]. Further, it should be stressed that the nature of R, at least that present in the overwhelming majority of zinc-triad xanthate structures, does not exert a significant influence upon the electronic structure of the xanthate anion [49].…”

“…Crystals 2018, 8, x FOR PEER REVIEW 4 of 32 and in the structural chemistry of related organotin carboxylates [43][44][45], where bulky groups can disrupt secondary bonding interactions [18,[46][47][48]. Further, it should be stressed that the nature of R, at least that present in the overwhelming majority of zinc-triad xanthate structures, does not exert a significant influence upon the electronic structure of the xanthate anion [49].…”

Structural characterization of dimethyl‐ and di‐n‐butyltin(IV) 2,3‐pyridinedicarboxylate in solution and in the solid state

“…For the related monomeric hepta-coordinated [R 2 Sn(2-picolinate) 2 (DMSO)] complexes, values of δ = −444 ppm (R = Me) and δ = −465 ppm have been reported. 32 Generally, there is a shift difference between dimethyl-and di-n-butyltin species due to the different electronic properties of the substituents and the chemical shift difference between Me 2 SnCl 2 (δ = 141 ppm) and nBu 2 SnCl 2 (δ = 122 ppm) can be taken as reference in order to evaluate the influence of the methyl and n-butyl groups on the 119 Sn NMR shift displacements. 45 The fact that the shift difference between 1 and 2 is more than 20 ppm, namely δ = 42 ppm, may indicate that the Lewis acidity of the dimethyltin(IV) derivative 1 is somewhat higher.…”

“…29 Similar observations have been made for a series of related diorganotin derivatives of 2-picolinic acid. 32 The most relevant crystallographic data for 1-DMSO, 2-H 2 O and 2-MeOH have been summarized in Table 2 Main Group Metal Compounds and the repeating fragments in their polymeric structures are shown in Figs 1 and 2, respectively. Selected bond lengths, bond angles and torsion angles are collected in Table 3.…”