Ring opening of dilithio bis(amido)cyclodiphosphazanes as a route to 1,3-diaza-2λ2-phosphaallyl gallium complexes

Gallium trichloride reacted with [((BuNP)-Bu-t)(2)((BuNLi)-Bu-t . THF)(2)] or [((BuNP)-Bu-t)(2)(PhNLi . THF)(2)] to form {[((BuNP)-Bu-t)(2)((BuN)-Bu-t)(2)]GaCl}, 1, and {[((BuNP)-Bu-t)(2)(PhN)(2)]GaCl . THF}, 3, respectively. Treatment of either gallium complex with [((BuNP)-Bu-t)(2)-((BuNLi)-Bu-t . THF)(2)] produced {[((BuNP)-Bu-t)(2)(RN)(2)]Ga((BuNPNBu)-Bu-t-Bu-t)}, R = Bu-t (2), R = Ph (4), respectively. The complexes 1 and 2 were X-ray structurally characterized, and 2 was shown to contain a 1,3-diaza-2 lambda(2)-phosphaallyl ligand. Compound 1 has C-s symmetry and crystallizes with two molecules in a monoclinic unit cell, space group P2(I)/m (No. 11), having dimensions (213 K) a = 9.5478(6) Angstrom, b = 11.9540(7) Angstrom,c = 97.808(1) Angstrom, beta = 97.808(1)degrees. The crystal data (213 K) for 2 are orthorhombic, space group Pnma (No. 62), a = 19.0514(2) Angstrom, b = 17.5082(1) Angstrom, c = 9.6695(1) Angstrom, and Z = 4.