1366629-58-4Relevant academic research and scientific papers
Neutral and anionic antimony(III) species supported by a bicyclic guanidinate
Day, Benjamin M.,Coles, Martyn P.,Hitchcock, Peter B.
, p. 841 - 846 (2012)
Bicyclic guanidine 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (hppH) was investigated as a source of anionic or neutral ligand at antimony. Reaction of the in situ generated lithium guanidinate with SbCl3 in a 1:1 or 2:1 ratio forms the expected metathesis products Sb(hpp) nCl3-n (1, n = 1; 2, n = 2). The molecular structures of 1 and 2 were determined by X-ray diffraction, which shows chelating guanidinates and suggests the presence of a stereochemically active lone pair of electrons. The reaction of two equivalents of the neutral guanidine hppH with SbCl 3 proceeds via proton transfer between the hpp fragments, affording the ion pair [hppH2][Sb(hpp)Cl3] (3), where [Sb(hpp)Cl3]- is an unusual example of a monometallic antimonate(III) anion. The molecular structure of 3 shows hydrogen bonding between two of the chlorides and the NH functionalities of the guanidinium cation. Bicyclic guanidinate [hpp]- (hppH = 1,3,4,6,7,8-hexahydro-2H- pyrimido[1,2-a]pyrimidine) chelates to antimony in Sb(hpp)Cl2 and Sb(hpp)2Cl. Attempted preparation of the neutral adduct with hppH afforded the salt [hppH2][Sb(hpp)Cl3], in which a net proton transfer between guanidine molecules had taken place. Copyright
