Ap. Purdy et al., LITHIUM DICYANAMIDE, ITS REACTIONS WITH CYANURIC CHLORIDE, AND THE CRYSTAL-STRUCTURES OF LIN(CN)(2)(MECN)(2) AND LICN(C5H5N)(2), Polyhedron, 16(20), 1997, pp. 3671-3679
Reactions of dicyanamides with cyanuric chloride were investigated as
possible routes to carbon nitrides. Anhydrous lithium dicyanamide (1)
was synthesized from NaN(CN)(2) and LiCl in THF. Compound 1 was found
to react with cyanuric chloride to form a yellow product, which forms
an amorphous lithium-carbon nitride with an approximate formula CN0.7L
i0.2 upon thermolysis to 700 degrees C. Upon heating to 1000 degrees C
, the product decomposes with the distillation of lithium cyanide. Rea
ctions between cyanuric chloride and trimethylstannyl dicyanamide were
also investigated. Lithium dicyanamide was also found to trimerize an
d polymerize at 280-320 degrees C. Additionally, two Li-C-N complexes
were structurally characterized. The bis (acetonitrile) adduct of 1 cr
ystallizes with the lithium atoms linking the cyano nitrogens into inf
inite Li-N=C-N-C=N-chains, and the bis(pyridine) adduct of LiCN consis
ts of infinite zig-zag -Li-C=N-chains. (C) 1997 Elsevier Science Ltd.