In Situ Generated Hydrated Diorganotin Cations as Synthons for Hydrogen-Bonded and Coordination-Driven 1D-, 2D-, and 3D-Assemblies

2010-07-07T00:00:00Z (GMT) by Vadapalli Chandrasekhar Puja Singh
The reaction of di-n-butyltin oxide with 1,5-naphthalenedisulfonic acid tetrahydrate in a 2:1 ratio afforded [{n-Bu2Sn(μ-OH)}2{μ-1,5-C10H6(SO3)2}]n (1). The latter is a three-dimensional coordination polymer, in a honeycomb architecture, containing [Sn2(μ-OH)2] repeat units that are connected to each other by the bridging coordination action of the disulfonate ligand. Reaction of [n-R2SnO]n (R = n-Bu or Ph) with 1,5-naphthalenedisulfonic acid tetrahydrate in a 1:1 ratio followed by reaction with bifunctional N-oxide ligands (4,4′-bipyridine-N,N′-dioxide (BPDO-II), 1,3-bis(4-pyridyl)propane-N,N′-dioxide (BPDO-III), or P-oxide (1,2-bis(diphenylphosphoryl)ethane (DPPOE)) ligands afforded, depending on the stoichiometry/reaction conditions, various compounds: [{n-Bu2Sn(BPDO-II)2(H2O)2}{1,5-C10H6(SO3)2}] (2); [n-Bu2Sn(μ-BPDO-II)(μ-1,5-C10H6(SO3)2)]n (3); [n-Bu2Sn(μ-DPPOE)(μ-1,5-C10H6(SO3)2)]n (4); [{Ph2Sn(μ-BPDO-II)(H2O)2}{1,5-C10H6(SO3)2}·2H2O]n (5·2H2O); [{n-Bu2Sn(μ-BPDO-III)2}{1,5-C10H6(SO3)2}·5H2O]n (6·5H2O); [{n-Bu2Sn(BPDO-III-H)2}{μ-1,5-C10H6(SO3)2}{1,5-C10H6(SO3)2}]n (7); and [{n-Bu2Sn(DPPOE)2}{μ-1,5-C10H6(SO3)2}2{n-Bu2Sn(CH3OH)(μ-OH)}2·2H2O]n (8·2H2O). On the other hand, the reaction of [n-Bu2SnO]n with 1,5-naphthalenedisulfonic acid tetrahydrate in a 2:1 ratio followed by nicotinic acid N-oxide multifunctional ligand (NO-IV) afforded [(n-Bu2Sn)(μ-1,5-C5H4(NO)(COO))2(μ-1,5-C10H6(SO3)2)(n-Bu2Sn)(H2O)(CH3OH)·CH3OH]n (9·CH3OH) and [(Bu2Sn)(H2O)(μ-1,5-C5H4)(NO)(COO))(μ-1,5-C10H6(SO3)2)1/2]n (10). While 2 is a molecular compound, 3 is a coordination polymer containing both sulfonate and N-oxide bridges. 4 is isostructrual with 3 except that the ligand involved is a bifunctional P-oxide ligand. 5 also is a coordination polymer, although, in this case, only the N-oxide ligands are in the coordination sphere of tin. 6 is a coordination polymer containing interlinked 28-membered macrocycles which are formed as a result of the flexible nature of the BPDO-III ligand. In contrast, in 7 one end of the BPDO-III ligand is protonated and hence does not take any part in coordination to tin. In this case, the coordination polymer is formed by the exclusive coordination action of the disulfonate ligand. Compound 8 reveals it to be a coordination polymer containing alternately [Sn2(μ-OH)2] and a discrete tin unit that are connected by disulfonate ligands. The coordination polymers 9 and 10 are obtained by a variation of crystallization conditions in the three-component reactions using NO-IV as the bridging ligand. While 9 is a neutral porous 2D-coordination polymer consisting of two different types of interconnected diorganotin units, 10 is a nonporous 2D-framework containing only one type of diorganotin unit. Most of the compounds prepared in this study showed good thermal stability, as indicated by their thermogravimetric analyses.