ON THE REACTION OF DIORGANODIHYDROXYSILANES WITH (t-Bu2SnO)3. SYNTHESIS AND CHARACTERISATION OF A NOVEL STANNASILOXANE COMPLEX AND ITS DISSOCIATION IN SOLUTION

Abstract

The complex [Ph 2 Si(OSnf-Bu 2 ) 2 Of-Bu 2 Sn(OH) 2 ] (2) was obtained in high yield by reaction of Ph 2 Si(OH) 2 with (f-Bu 2 SnO) 3 (1). Reaction of f-Bu 2 Si(OH) 2 with 1 gave [t-Bu 2 Si(0Snf-Bu 2 ) 2 0] (4a) instead. The compounds were investigated by means of NMR, IR, MOssbauer spectroscopy, and in case of 2 by X-ray analysis. In solution, 2 is in equilibrium with [Ph 2 Si(0Snf-Bu 2 ) 2 0] (2a), 1, and water. i-Bu 2 Sn(OH) 2 (3) was prepared by controlled hydrolysis of f-Bu 2 Sn(OMe) 2 and was shown to undergo condensation with formation of 1. Mössbauer studies as well as 11 ®Sn CP MAS NMR including side band analysis suggest 3 to exhibit a dimeric structure with pentacoordinate tin. Similar studies on 1 suggest fast rotation of the molecule in the crystal lattice. Abstract (f-Bu 2 SnO) 3 + Ph 2 Si(OH) 2 1 toluene, 60° C, 1d [Ph 2 Si(0Snf-Bu2)2Of-Bu 2 Sn(0H)2] (1) 2 113 Brought to you by | Purdue University Libraries Authenticated Download Date | 6/11/15 12:28 AMThe 119 Sn CP MAS NMR spectrum of 2 shows two signals at -265.7 and -273.7 ppm, respectively, with an integral ratio of 1:2 which is in line with the structure established by the X-ray measurement. The IR spectrum shows the presence of the OH groups by a (OH) of 3644 cm" 1 .

The Isoelectronic Replacement of E = P+ and Si in the Trinuclear Organotin−Oxo Clusters [Ph2E(OSntBu2)2O·tBu2Sn(OH)2]

“…Consistent with the 119 Sn chemical shifts in solution and the molecular structure established by X-ray diffraction, the 119 Sn MAS NMR spectrum of 6 shows two signals at δ ϭ 6a, E ϭ P ϩ , 1, E ϭ Si, [9] 5, E ϭ Si, [13] X Ϫ246.1 and Ϫ277.9 with an integral ratio of 39:61 and accompanying sets of spinning sidebands. The sets of spinning sidebands were used to perform a tensor analysis according to the method of Herzfeld and Berger; [16] the results are collected along with those of the stannasiloxane 1 in Table 3.…”

“…(ii) The Sn(1)ϪX(1) and Sn(2)ϪX(2) distances increase on going from 6 to 1 and then 5, which is consistent with the dissociation of compound 1 in solution, as shown by variable temperature 119 Sn NMR spectroscopy. [9] (iii) The Sn(1)ϪO(2) and Sn(2)ϪO(3) distances also decrease in the order 6 Ͼ 1 Ͼ 5. (iv) The geometrical goodness ∆Σ(θ) [15] of the trigonal bipyramidal configurations for Sn(1) and Sn (2), is best for compound 6.…”

“…The consecutive reaction of di-tert-butyltin oxide with triflic acid and diphenylphosphinic acid provided the trinuclear organotinϪoxo cluster [ Figure 1; selected bond lengths and angles are collected in Table 1 (1), [9] F (5) [13] ], the [PSn 3 O 3 (OH) 2 ] structural motif of 6a is almost planar, the largest deviation from the plane being 0.033(3) Å . All three tin atoms show slightly distorted trigonal bipyramidal configurations [geometrical goodness [15] ∆Σ(θ) ϭ 89.0°for Sn(1), 89.6°for Sn(2), 90.1°for Sn(3)], in which two carbon (2) Sn (1)ϪO (2) 2.192(3) Sn (1)ϪO (1) Sn (1)ϪO (4) 2.138 (2) Sn (1)ϪC (10) 2.183(4) Sn (1)ϪC (20) 2.187 (4) Sn (2)ϪO (1) 2.075(2) Sn(2)ϪO (3) 2.200 (3) Sn (2)ϪO (5) 2.134(3) Sn (2)ϪC (30) 2.181 (4) Sn (2)ϪC (40) 2.185(4) Sn (3)ϪO (1) 2.152 (2) Sn (3)ϪO (4) 2.109(3) Sn(3)ϪO (5) 2.106 (3) Sn (3)ϪC (50) 2.188(4) Sn (3)ϪC (60) 2.180 (4) P (1)ϪO (2) 1.509(3) P(1)ϪO (3) 1.493 (3) P (1)ϪC (70) 1.795(4) P(1)ϪC …”

“…[1Ϫ8] In this regard, we and others have reported a variety of trinuclear organotinϪoxo clusters [M(OSntBu 2 ) 2 O·tBu 2 Sn(OH) 2 ] [M ϭ Ph 2 Si (1), [9] Me 2 Si (2), [10] CO (3), [11] and MesB (4) [12] ] and [Ph 2 Si(OSntBu 2 ) 2 O·tBu 2 SnF 2 ] (5) [13] that adopt a common tricyclic, almost planar ESn 3 O 3 X 2 (E ϭ Si, C, B; X ϭ OH, F) structural motif (Scheme 1). It was proposed that further examples of this class of compound might be accessible upon replacement of E by other organometallic fragments.…”

Diorganotin Salicylaldoximate Clusters: Their Fascinating Chemistry and Structures

“…This suggests that the soluble cluster could act as an in situ reservoir of soluble diorganotin oxide, although this remains to be proven. [17,18] Upon dissolution of monocrystalline 1 in CDCl 3 , intense 119 Sn NMR resonances are observed for cluster 1, together with other minor resonances that were assigned to other species as discussed below. Thus, a set of three minor, 119 Sn resonances were assigned to another cluster, 2, that was subsequently synthesized independently from the reaction:…”