Nonconventional Behavior of NCN-Chelated Organoantimony(III) Sulfide and Isolation of Cyclic Organoantimony(III) Bis(pentasulfide)

Abstract

Organoantimony(III) sulfide (1) containing the NCN chelating ligand L [L = 2,6-(CH(2)NMe(2))(2)C(6)H(3)] displays unusual dual behavior, being dimeric (LSbS)(2), with the central Sb(2)S(2) core, in the solid state but monomeric in solution. Sulfide 1 reacts with elemental S to give the unprecedented cyclic bis(pentasulfide) LSb(mu-S(5))(2)SbL (2) with the central 12-membered ring Sb(2)S(10).

Synthesis and Structure of NCN‐Chelated Organobismuth(III) Bis‐Pentasulfide

“…The polysulfide chains are anchored to the central bismuth atoms with the bond lengths Bi(1)–S(1) 2.7652(17), Bi(1)–S(4) 2.7506(17) Å, which are longer than the proposed value for the Bi–S single covalent bond (2.54 Å)9 indicating significant polarity of these Bi–S bonds in 2 . Similar elongation of Sb–S bond lengths has recently been obtained for the antimony analogue LSb(μ‐S 5 ) 2 SbL 6. This fact indicates that due to the high polarity of theses M –S bonds ( M = Sb, Bi) in both cases significant negative charge may be localized on the sulfur atom, whereas the central metal atom antimony or bismuth carries positive charge, which is stabilized by strong intramolecular N→ M interactions.…”

“…Moreover upon standing of 2 in CD 2 Cl 2 solution a complete decomposition occurred within several days. Unfortunately, comparison of the solution structure with the antimony congener LSb(μ‐S 5 ) 2 SbL was hampered by insolubility of the antimony compound 6…”

“…This reaction produced unprecedented cyclic bismuth bis‐pentasulfide 2 , where two bismuth atoms are bridged by two symmetrical μ‐S 5 bridges, representing a new structural type among organobismuth (poly)sulfides. The only analogue found in the literature is its antimony congener LSb(μ‐S 5 ) 2 SbL 6…”

“…By analogy, we have shown that organoantimony and organobismuth sulfides (L M S) 2 {L = [2, 6‐(CH 2 NMe 2 ) 2 C 6 H 3 ] – , M = Sb, Bi ( 1 )}, which are split to their monomeric forms with terminal M –S bonds in solution, are able to activate carbon disulfide5 and in the case of the antimony compound also elemental sulfur 6. Herein, we report activation of S 8 by organobismuth sulfide ( 1 ) with formation of unprecedented cyclic bis‐pentasulfide LBi(μ‐S 5 ) 2 BiL ( 2 ).…”

Synthesis, Structure and Applications of Hypervalent Organoantimony Compounds Having Intramolecular E→Sb (E = N, O, S) Coordinations

“…3). [69,70]. The dimeric oxide 59 reacted with CO 2 in a toluene solution to give carbonate ArSbCO 3 (61) (Scheme 19).…”