Picture of smart phone in human hand

World leading smartphone and mobile technology research at Strathclyde...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of Open Access research papers by University of Strathclyde researchers, including by Strathclyde researchers from the Department of Computer & Information Sciences involved in researching exciting new applications for mobile and smartphone technology. But the transformative application of mobile technologies is also the focus of research within disciplines as diverse as Electronic & Electrical Engineering, Marketing, Human Resource Management and Biomedical Enginering, among others.

Explore Strathclyde's Open Access research on smartphone technology now...

Lithiations of mercaptoamines containing NC(S)NH–,–NHC(S)S– and –NHC(S)NH– units: syntheses, crystal structures and model molecular-orbital calculations

ARMSTRONG, D R and Mulvey, Robert and BARR, D and PORTER, R W and RAITHBY, P R and SIMPSON, T R E and SNAITH, R and WRIGHT, D S and GREGORY, K and MIKULCIK, P (1991) Lithiations of mercaptoamines containing NC(S)NH–,–NHC(S)S– and –NHC(S)NH– units: syntheses, crystal structures and model molecular-orbital calculations. Journal of the Chemical Society, Dalton Transactions (S). pp. 765-776. ISSN 0300-9246

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

Three mercaptoamines have been lithiated in the presence of various Lewis bases. 2-Mercaptopyrimidine (I), containing a = NC(= S)NH- (as an amine)/ = NC(-SH)= N- (as a thiol) unit, affords [N activated = CHCH = CH(N..C..S)Li.hmpa]n 1. 2-Mercaptothiazoline (II), with a -SC(= S)NH-/-SC(-SH) = N- unit, gives [S activated CH2CH2(N..C..S)Li.tmen]n 2. 2-Mercaptobenzimidazole (III), having a -NHC(= S)NH-/-NHC(-SH) = N- unit, gives, when dilithiated, { activated C6H4[N..C(..S)..N]Li2.3hmpa}n 3 [hmpa = hexamethylphosphoramide, (Me2N)3P = O; tmen = Me2NCH2CH2NMe2]. The solid-state structures of complexes 1-3 were solved by X-ray crystallography. Complex 1 is polymeric (n = infinity): each unit contains a (N..C..S)Li chelate feature with a terminal hmpa molecule on Li, and these units are then associated via intermolecular N-->Li co-ordinations using the third (N) heteroatom of the organic anion. Complex 2 is a dimeric (n = 2) S-Li compound with each Li bearing a tmen molecule; dimerisation is achieved by N-->Li intermonomer interactions, but the third (ring S) heteroatom is not involved with metal centres. The dilithiated species 3 is also a dimer (n = 2) and each Li is chelated by an N..C..S unit of its organic dianion; the two end-Li atoms of the dimer are each co-ordinated to two terminal hmpa molecules, while the two central Li atoms are linked by two mu-hmpa molecules, which effect dimerisation. The structural diversities displayed by 1-3 have been probed, and thereby in part rationalised, by ab initio (6-31G basis set) and MNDO molecular-orbital calculations on the amine/thiol isomers of I-III, and on their uncomplexed and complexed lithiated derivatives (as monomers). In particular, the optimised structures predict and reproduce the (N..C..S)Li chelating modes found in 1 and 3, and help to explain why direct S-Li bonding is found in 2.