Preparation and properties of sterically demanding and chiral distibine ligands

Abstract

A series of new rigid distibines, 1,8-bis(R(2)Sb)naphthalene (R = Me: (); R = Ph: ()), and chiral distibines, 2,2'-bis(R(2)Sb)-1,1'-binaphthyl (R = Me: (); R = Ph: () obtained as racemic mixtures) and the discrete enantiomers of 4,5-bis((R(2)Sb)methyl)-2,2-dimethyl-1,3-D/L-dioxolane (R = Me: () (l), () (d); R = Ph: () (l), () (d)) have been obtained in high yields, using either electrophilic halostibine reagents with di-lithium reagents (()-()) or nucleophilic stibide reagents with dibromo-derivatives (()-()). The distorted octahedral complexes [Mo(CO)(4)(L)], L = ()-(), planar [PtCl(2)(L)], L = (), (), (), (), and neutral, five-coordinate [RhCl(cod)(L)], L = (), (), (), are reported and trends in the spectroscopic data are discussed in terms of the ligand donor properties. Crystal structures of () and [Mo(CO)(4)()] reveal significant structural changes occur upon coordination, and these are also reflected in the solution NMR spectroscopic parameters. Changes in the C-Sb-C angles and C-Sb bond distances upon coordination of () are discussed in term of increased s/p orbital mixing. Air oxidation of () forms a very unusual stibine oxide, the structure of which shows a distorted Sb(4)O(4) cubane core (bridging O atoms) with two orthogonal naphthalene units.

Synthesis, structure and dispersion interactions in bis(1,8-naphthalendiyl)distibine

“…The av. Sb-C bond length in 1 (2.1637(19) Å) is comparable to those reported for 1,8-(R2Sb)2-C10H8 [11] and matches values found in the CSD (1.756 -2.406 Å, mean 2.136(36) Å). The molecular structure of Naph2P2, the P-analogue of 1, is similar to that of 1.…”

“…The 1,8-naphtalendiyl ligand (Naph) is a promising ligand due to its capability to stabilize group 15 elements, [10] i.e. 1,8-(R2Sb)2Naph, [11] chalcogen- [12] and P/chalcogen-substituted compounds. [13,14] We now report on the synthesis of Naph 2Sb2 1 and the role of dispersion interactions on the solid state structure.…”

Synthesis of ligands based on naphthalene peri-substituted by Group 15 and 16 elements and their coordination chemistry

“…With regards to Group 15 chemistry, rather promisingly the synthesis of the NapSb 2 ligands was recently demonstrated to be comparable in yields to well established NapP 2 species [76]. This indicates that the synthesis of bismuth species may be possible, and opens up the possibilities of synthesising mixed donor ligands with different Group 15 elements as peri-atoms.…”

“…Naphthalene bis(stibines) 93a,b were synthesised recently via a route normally used in phosphine chemistry, with good yields (Scheme 41) [76]. 93a,b behave as chelating ligands towards Pt(II), Mo(0) and Rh(I) metal centres.…”

Naphthalene and Related Systems peri‐Substituted by Group 15 and 16 Elements

“…[91,92] 1,8-Dilithionaphthalene served as a starting material in the syntheses of distibines 78. [93] A partially oxidised product 79 has been structurally characterised (Scheme 45).…”