Reactions of in situ generated hydrated organotin cations with chelating O,O- or O,N-ligands: a possible structure-directing influence of the organic substituent on tin

Abstract

The reaction of [n-Bu₂SnO]_n with 1,5-naphthalenedisulfonic acid tetrahydrate in a 1 : 1 stoichiometry followed by reaction with 2,2′-bipyridine-N,N′-dioxide (BPDO-I) afforded a 1D-coordination polymer [n-Bu₂Sn(BPDO-I)(1,5-C₁₀H₆(SO₃)₂)]_n (1) where the disulfonate ligand acts as a bridging ligand between two tin centers. An analogous reaction involving [Ph₂SnO]_n afforded a trihydrated O,O′-chelated diorganotin cation [{Ph₂Sn(BPDO-I)(H₂O)₃}²⁺][C₁₀H₆(SO₃⁻)₂]·2CH₃OH (2·2CH₃OH). Utilizing two equivalents of BPDO-I in this reaction resulted in the ionic complex [{Ph₂Sn(BPDO-I)₂(H₂O)}²⁺][C₁₀H₆(SO₃⁻)₂]·3H₂O (3·3H₂O). In 2 and 3 the sulfonate ligands are not present in the coordination sphere of tin. Reaction of [n-Bu₂SnO]_n and 1,5-naphthalenedisulfonic acid tetrahydrate, followed by reaction with [bis(diphenylphosphoryl)methane (DPPOM)] resulted in the formation of, [{n-Bu₂Sn(DPPOM)₂(H₂O)(1,5-C₁₀H₆(SO₃)(SO₃⁻)}]·H₂O (4·H₂O). Of the two coordinating groups present in DPPOM, only one PO group is coordinated to the tin atom. The remaining PO motif is free and is involved in intramolecular H-bonding with the tin-bound water molecule. Using [Ph₂SnO]_n instead of [n-Bu₂SnO]_n afforded the ionic complex [{Ph₂Sn(DPPOM)₂}²⁺{1,5-C₁₀H₆(SO₃⁻)₂}] (5) where the DPPOM functions as a chelating ligand. The reaction of [n-Bu₂SnO]_n with 1,5-naphthalenedisulfonic acid tetrahydrate followed by addition of one equivalent of 8-hydroxyquinoline (8-HQ) in presence of triethylamine afforded the neutral dinuclear complex, [(H₂O)(8-Q)n-Bu₂Sn(μ-1,5-C₁₀H₆(SO₃)₂)n-Bu₂Sn(8-Q)(H₂O)] (6) where the two tin atoms are bridged by the disulfonate ligand. Compounds 1–6 are thermally stable as shown by their thermogravimetric analyses.