Hypercoordinated organotin(IV) compounds containing C,O- and C,N- chelating ligands: Synthesis, characterisation, DFT studies and polymerization behaviour

Preparation and DFT Studies of κ2C,N-Hypercoordinated Oxazoline Organotins: Monomer Constructs for Stable Polystannanes

“…In the case of 10, observed crystallographic disorder is consistent with the presence of two oxazoline ring twist isomers that are resolvable due to the Sn hypercoordination. The MSSDs observed for 7, 9, and 10 are comparable with those measured for Sn complexes with phenyl ligands in the previous study [17]. In all cases, there is evidence of some distortion in the solid-state structures, typically seen in the bending of a phenyl ligand at the coordinating C atom, such that the Sn-C(Ph) bond no longer lies in the plane of the phenyl ring.…”

“…Previous work has demonstrated that the LANL08d ECP for Sn and Br, and 6-31+G(d,p) for all other atoms provide accurate structures at moderate computational cost [39,40]. In a recent evaluation of selected density functionals, we found that B3PW91 [41] and PBE0 "PBE1PBE" [42] when supplemented with Grimme's D3 empirical dispersion function and Becke-Johnson damping (GD3BJ) [43] outperformed eight other methods in predicting hypercoordinate Sn geometries [17]. The use of diffuse functions on non-H atoms significantly improved accuracy as did augmenting methods with empirical dispersion.…”

“…The seven crystallographically determined structures in this study (compounds 4 (4 ,4"), 7, 9 (9 ,9"), 10, 11) provide a small structurally-related dataset to compare with DFT models. We have previously summarized the problematic aspects of comparing calculated and experimental structural data [17]; nevertheless, it remains a useful approach for refining a DFT description of these hypercoordinate systems. Previous work has demonstrated that the LANL08d ECP for Sn and Br, and 6-31+G(d,p) for all other atoms provide accurate structures at moderate computational cost [39,40].…”

“…Polystannanes bearing more rigid groups do not share the same level of flexibility, resulting from a presumed stronger dative interaction and greater steric bulk around the tin units. Recently, we disclosed details on the preparation of hypercoordinate polystannanes with either a benzyl κ 2 -C,N (dimethylamino) or a κ 2 -C,O (2-methoxymethyl) chelating group [17]. These materials are derived by dehydropolymerization of the respective -C,N and -C,O dihydride monomers using a late transition metal catalyst.…”

(N),C,N‐Coordinated Heavier Group 13–15 Compounds: Synthesis, Structure and Applications

“…The Ar CN ligand was also applied for the synthesis of C,N ‐chelated hydridostannates that served as starting materials for preparation of tin‐based inorganic polymers‐polystannates. These were prepared by dehydro‐coupling reaction with M w 30.3 kDa and PDI=1.4–1.86 (Scheme ) …”