Crystal structure, vibrational spectra, and normal coordinate analysis of (n-Bu4N)(2)[Os(NCS)(6)] and (n-Bu4N)(3)[Os(NCS)(6)]

By tempering the solid mixture of the linkage isomers (n-Bu4N)(3)[Os(NCS)(n )(SCN)(6-n)] n=0-5 for a longer time at temperatures increasing from 60 to 140 degreesC the homoleptic (n-Bu-4 N)(3)[Os(NCS)(6)] is formed, which on o xidation with (NH4)(2)[Ce(NO3)(6)] in acetone yields the corresponding Os-I V complex (n-Bu4N)(2)[Os(NCS)(6)]. X-ray structure determinations on single crystals of (n-Bu4N)(2)[Os(NCS)(6)] (1) (triclinic, space group P (1) over bar, a = 12.596(5), b = 12.666(5), c = 16.026(5) A, alpha= 88.063(5), beta = 80.439(5), gamma= 88.637(5)degrees, Z = 2) and (n-Bu4N)(3)[Os(NCS)(6)](2) (cubic, space group Pa (3) over bar, a=24.349(4)(A) over dot, Z=8) have be en performed. The nearly linear thiocyanate groups are coordinated with Os- N-C angles of 172.3-177.7 degrees. Based on the molecular parameters of the X-ray determinations the IR and Raman spectra are assigned by normal coord inate analysis. The valence force constant f(d)(OsN is 2.3 (1) and 2.10 mdy n/A (2).