The Crystal and Molecular Structure of Tetrameric Phosphonitrilic Isothiocyanate

Abstract

The crystal structure of tetrameric phosphonitrilic isothiocyanate, N4P4(NCS),, has been determined by three-dimensional X-ray studies from data collected on a Picker FACS-I automated diffractometer. The compound crystallizes in the triclinic space group P i with a = 8.098(8), b = 8.018(7), c = 9.937(10) A, a = 104.08(7), = 99.42(7), p = 95.42(7)", and one molecule per unit cell. The structure was solved from 1766 independent non-zero reflections and refined to a conventional R factor of 0.063. Nitrogen atoms of two isothiocyanate groups are bonded to each phosphorus atom of the eight-membered phosphorus-nitrogen ring. The ring has a chair configuration. The average dimensions of the structure are P-Nri,, = 1.543 + 0.017, P-NisOlhiOC yana,c = 1.644+0.011, N-C=1.168&0.008, C-S=1.535+0.009 A, P R r i n g P = 140.2+ 1.8", N,~,,~N,~,, = 120.2k 1.3", N~, ,~N~, , = 100.1 + 1.0", PRC= 151.1 k9.O0,and N~s = 176.6+ 1.1".La structure cristalline du tetramere de l'isothiocyanate phosphonitrilique, N4P4(NCS),, a kt6 determinee par diffraction de rayons-X a partir de donnees tridimensionnelles obtenues sur un diffractometre automatique Picker FACS-I.La maille trichinique de ce compose est monomoleculaire de dimensions: a = 8.098(8), b = 8.018 (7), c = 9.937(10) A, a = 104.08 (7), p = 99.42(7) et y = 95.42(7)", et appartient au groupe spatial P i .La structure a Cte dtterminke a partir de 1766 reflexions uniques observees et affinee jusqu'a une valeur de 0.063 du facteur d'accord R.A chaque atome de phosphore d u cycle a 8 atomes N4P4 sont liee deux groupes isothiocyanate par I'intermediaire de leur atome d'azote. Le cycle a la configuration chaise. Les dimensions moyennes de la structure sont: P-N(cycle) = 1.543(17), P-N(isothiocyanate) = 1.644(1 I), N-C = 1.168(8), C-S = 1.535(9) A, ~PN(cyc1e)P = 140.2(18)", L N(cycle)PN(cycle) = 120.2(13)", LN(iso)PN(iso) = 100.1 (lo)", L P N C = 151.1 (90)" et LNCS = 176.6(11)".

Synthesis of polyphosphazenes with isothiocyanato, thiourethane, and thiourea side groups

“…Again, the reaction stoichiometry was designed so that no PCI2 units would be present. The reaction of 21 with potassium thiocyanate then resulted in the formation of 22. Although the interaction of 22 with aniline in THF at 25 °C gave the thiourea derivative 23, no reaction was detected between 22 and methanol in THF at 66 °C. The reduced electrophilicity of the isothiocyanato groups of 22 can probably be attributed to the electron-releasing character and steric bulk of 2-(2-methoxyethoxy)ethoxy side groups.…”