Assignment of ³¹P Chemical Shifts to Isomers of 2,3-Dialkoxy-λ3-diazadiphosphetidines — Crystal and Molecular Structure of trans-[PhNP(OCH₂CF₃)]₂

Abstract

<jats:title>Abstract</jats:title><jats:p> Geometrical isomers of λ<jats:sup>3</jats:sup>-diazadiphosphetidines show large differences in their <jats:sup>31</jats:sup>P chemical shifts. Trifluoroethoxylation of cis-(PhNPCl)<jats:sub>2</jats:sub> gives only the 'low-field' isomer initially, for which the crystal structure is determined. The compound crystallises in the triclinic space group P1̄ with a = 9 .6 2 4 (4 ).6 = 10.107(4),c = 11.140(7) Å ; a = 105.65(4),β = 110.59(4),y = 93.82(3)°;and Z = 2. The structure was solved by direct methods and refined to R = 0.045. The alkoxy groups are trans to each other. On standing in solution. trans -[PhNP(OCH<jats:sub>2</jats:sub>CF<jats:sub>3</jats:sub>)]<jats:sub>2</jats:sub> transforms slowly and almost completely into its cis analogue with a high field <jats:sup>31</jats:sup>P chemical shift</jats:p>

New 10-Membered Inorganic Heterocyclic Diphosphanes, PhN(PX)2{(−OC6H2(tBu)2)(μ-S)((tBu)2C6H2O−)} (X = Cl, F). Synthesis and Transition Metal Complexes (Molybdenum(0), Ruthenium(II), Palladium(II), and Platinum(II)) of Heterocyclic Diphosphanes. Crystal and Molecular Structures of the Chloro Derivative, PhN(PCl)2{(−OC6H2(tBu)2)(μ-S)((<

“…The two chlorine atoms are mutually cis and are located on the same side of the ring. The P(1)−N−P(2) bond angle of 109.15(18)° is larger than the average P−N−P bond angles (97°−100°) observed in cyclodiphosphazanes. − The bond angles around the nitrogen sum to 355.77°, indicating that the planar geometry around the amine nitrogen is retained. The P(1)−N (1.691(3) Å) bond is slightly shorter than the P(2)−N (1.718(3) Å) bond.…”