ISSN:
0948-5023
Keywords:
KeywordsAb initio calculation, Isomerism, Lithium, Solid-state structure, Sulphur
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Reaction of o-mercaptopyridine (o-MPH) and trithiocyanuric acid (TTCyH3) with one equivalent of BunLi in the presence of HMPA yields the mono-lithiated salts MPLi.HMPA (1) and TTCyH2Li.2HMPA (2) respectively, which have been characterised by NMR spectroscopy and X-ray crystallography. Reaction of three equivalents of BunLi with anhydrous TTCyH3 in THF yields the tri-lithiated species TTCyLi3.4THF (3). In all three compounds the lithium centres have N,S-bridged coordination modes. Whereas 1 is dimeric in the solid state, 2 has an unusual monomeric structure and 3, which is a very rare example of a structurally characterised tri-lithiated compound, has an unprecedented polymeric structure incorporating (NCSLi) n (n = 1, 2) rings. The structural diversities displayed by 1 and 2 have been probed, and thereby in part rationalised, by ab initio (6-31G*/RHF, 6-31G**/RHF and 6-31G*/MP2 levels) MO calculations on both their thio-keto and thiol isomers and on their uncomplexed and complexed lithiated derivatives. In particular, the optimised structures predict and reproduce the N,S-bridging coordination modes found for lithium and explain why structure 1 is dimeric whereas 2 is monomeric.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s0089400060234
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