Preparation of a Thallium(I) Diazotate. Structure, Physicochemical Characterization, and Conversion to Novel N-Nitroso Compounds

Article abstract of DOI:10.1021/ja00217a018

Thallium(I) (E)-methanediazotate (4) has been prepared and characterized.In contrast to previously reported methanediazotates, 4 is a highly crystalline material whose physical properties suggest a considerable degree of covalency: it is readily soluble in certain nonpolar solvents; it melts reversibly at a low temperature; it is monomeric and nonconducting in chloroform solution; and ions corresponding to the formula Tl(CH3N2O)^.+ are found in the electron impact mass spectrum.The crystal structure of 4 revealed Tl-O distances as short as 2.52(3) Angstroem and confirmed the anti stereochemistry; the monoclinic unit cell, space group P2₁/c-C⁵_2h (No. 14), had a=13.233(6) Angstroem, b=11.594(4) Angstroem, c=6.253(2) Angstroem, β=119.45(3)^o, V=871.5(6) Angstroem³, and Z=8.The compound's advantageous stability and solubility properties provide important new opportunities for probing the solution chemistry of the alkanediazotates.As an illustration of this potential, 4 has been converted in homogeneous media to unusual N-nitroso compounds including a quaternary ammonium salt of a primary nitrosamine, an isotopic variant of dimethylnitrosamine in which the methyl group syn to the oxygen is fully deuteriated, and the less stable Z conformer of methylbenzylnitrosamine.In contrast to 4 , its Z stereoisomer has until now defied isolation but has been identified in situ by reaction with iodomethane-d₃ to produce (E)-methyl(methyl-d₃)nitrosamine.