Synthesis, crystal structure, vibrational spectra, and normal coordinate analysis of (Ph4P)2[OsN(N3)5] and 15N NMR chemical shifts of nitridoosmates(VI, VIII)

The treatment of (Ph4P)[OsNCl4] with NaN3 yields (Ph4P)(2)[OsN(N-3)(5)], which crystal structure has been determined by single crystal X-ray diffraction analysis (monoclinic, space group P2(1)/a, a = 20.484(6), b = 11.168(1), c = 20.666(4)Angstrom, beta = 97.35(3)degrees, Z = 4). The IR and Raman vibrations were assigned by a normal coordinate analysis based on the molecular parameters of the X-ray determination. The valence force constants are f(d)(Os equivalent to N) = 8.52, f(d)(Os-N-alpha) = 1.99, f(d)(N-alpha-N-beta) = 12.42, f(d)(N-beta-N-gamma) = 12.73 and for the azido ligand in trans-position to the nitrido group f(d)(Os-N-alpha.) = 1.84, f(d)(N-alpha.-N-beta.) = 11.91, f(d)(N-beta-N-gamma.) = 12.18 mdyn/A. The N-15 NMR spectra of various nitridoosmates reveal the chemical shifts delta(N-15) for K[(OsO3N)-N-15] = 387.61 K-2[(O8NCl5)-N-15] = 446.7, (Ph4P)[(OsNCl4)-N-15] = 352.9, [(n-C6H13)(4)N](2)[(OsN)-N-15(N-3)(5)] = 307.3 and for [(n-Pr)(4)N](2)[(OsN)-N-15((NCO)-N-15)(5)] = 483,7 (Os equivalent to N), -417,7 (OsNCOeq) und -392,8 ppm (OsNCOax).