Inorganic Chemistry, Vol.37, No.13, 3263-3268, 1998
Hybrid sulfanuric-phosphazene ring systems : Synthesis, spectroscopic characterization, and X-ray structures of trans-Ph4P2N4[S(O)R](2) (R = Ph, Me), cis-Ph4P2N4[S(O)Me](2), and R4P2N4(SNMe2)(2) (R = Ph, Et)
The reaction of the chair form of Ph4P2N4(SR)(2) (R = Ph, Me) or the boat form of Ph4P2N4(SMe)(2) With an excess of m-chloroperbenzoic acid in THF produces trans-Ph4P2N4[S(O)R](2) (4a, R = Ph; 4b, R = Me) or cis-Ph4P2N4[S(O)Me](2) (4b), respectively..The structures of trans-4a, trans-4b, and cis-4b were determined by:X-ray crystallography, which revealed twist-boat conformations for the P2N4S2 rings. The S-N bond distances decrease by ca. 0.06 Angstrom and the angle NSN bond angles increase by ca. 3-4 degrees : upon oxidation of the S(IV) centers to S(VI). Crystals data : trans-4a, monoclinic, P2(1)/n, a = 10.173(3) Angstrom, b = 18.030(3) Angstrom, c = 17.920(2) Angstrom, beta = 91.47(1)degrees, V = 3285(1) Angstrom(3), Z = 4; trans-4b, monoclinic, P2(1)/n, a = 10.616(2) Angstrom, b = 17.833(3) Angstrom, c = 14.133(5) Angstrom, beta = 97.00(3) Angstrom, V = 2655(1) Angstrom(3), Z = 4; cis-4b, monoclinic, P2(1)/n, a = 10.536(3) Angstrom, b = 17.219(2) Angstrom, c = 15.085(3) Angstrom, beta = 109.45(2)degrees, V = 2580.5(9) Angstrom(3), Z = 4. The reaction of R4P2N4(SCl)(2) With 2 equiv of Me2SiNMe2 in THF at -78 degrees C yields R4P2N4(SNMe2) (5a, R = Ph; 5b, R = Et) in which the P2N4S2 rings adopt chair (5b) or distorted chair (5a) structures. Crystals data : 5a, triclinic, P (1) over bar, a = 9.891(4) Angstrom, b = 10.123(6) Angstrom, c = 8.759(4) Angstrom, alpha = 113.12(3)degrees, beta = 111.82(3)degrees, gamma = 64.28(4)degrees, V = 704.9(7) Angstrom(3), Z = 1; 5b, monoclinic, P2(1)/c, a = 8.144(2) Angstrom, b = 15.548(3) Angstrom, c = 8.250(2) Angstrom, beta = 109.24(2)degrees, V = 986.3(4) Angstrom(3), Z = 2. The thermolysis of 5b at 80 degrees C yields Et4P2N4S2 as the final product.