Access to new Janus head ligands: linking sulfur diimides and phosphanes for hemilabile tripodal scorpionates

• Published in: Dalton transactions : an international journal of inorganic chemistry Vol. 40; no. 8; pp. 1662 - 1671
• Main Authors: Meinholz, Margret M, Pandey, Sushil K, Deuerlein, Stephan M, Stalke, Dietmar
• Format: Journal Article
• Language: English
• Published: England 01.01.2011
• Subjects: Diimide; Janus; Ligands; Lithium; Magnesium; Nitrogen atoms; Sulfur
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c0dt00665c

Reactions of lithium dialkyl/phenyl phosphanylmethylides, RR'PCH(X)Li (R, R' = Me, Et, Ph and R = Me, R' = Ph; X = H or Me), with sulfur diimides S(NR'')2 (R'' = (t)Bu or SiMe3) in an equimolar ratio yielded Janus head complexes with the structural motif [Li{RR'PCH(X)S(NR'')2}]2 (R'' = (t)Bu, SiMe3). The basic core of these dimeric complexes is composed of a (LiN)(2) four-membered ring containing two four-coordinated lithium atoms. A lithium complex of the new Janus head ligand with another structural motif [TMEDA·Li{Ph(2)PCH(2)S(NSiMe3)2}] (6) could be isolated from the reaction of [Ph2PCH2Li·TMEDA] with S(NSiMe3)2. Two monomeric complexes [Mg{Me2PCH2S(NR'')2}2] (7, 8) were synthesised by a straightforward reaction of [Li{Me2PCH2S(NR'')2}2] with MgCl2 in pentane. The magnesium atom is chelated by one phosphorus atom and two nitrogen atoms of each unit of the hemilabile ligand in a tripodal manner, leading to octahedral geometry around the magnesium cation. A complete analysis of [Ph2PCH2(SNSiMe3)(HNSiMe3)] (9) is also described in which one nitrogen atom of the imido moiety is protonated.