Crystal Structure and Spectroscopic and Magnetic Properties of the Manganese(II) and Copper(II) Azido-Tetramethylammonium Systems.

The compounds [N(CH3)4][Cu(N3)3] (1) and [N(CH3)4][Mn(N3)3] (2) have been synthesized and characterized. Compound 1 crystallizes in the monoclinic P21/n space group, with Z = 4, a = 7.473(2) A, b = 15.780(2) A, c = 9.321(2) A, and β = 92.59(2)°. Compound 2 crystallizes in the monoclinic P21 space group, with Z = 2, a = 6.264(3) A, b = 13.150(6) A, c = 6.375(3) A, and β = 90.00(6)°. At high temperature, compound 2 undergoes a structural phase transition toward a pseudocubic phase with a = 6.446(4) A. The nature of the metallic ion remarkably influences the molecular structure of both compounds. Thus, while compound 1 is one-dimensional, with the copper(II) ions bridged by one end-on (EO) and two end-to-end (EE) azido ligands, the structural arrangement in compound 2 is three-dimensional, the manganese(II) ions being bridged by EE azido ligands. In both cases, tetramethylammonium cations stabilize the negative charge of the [M(N3)3]- fragments. Magnetic susceptibility measurements show antiferromagnetic cou...