Aryl-substituted phosphonitrilic fluorides. IV. The crystal and molecular structure of 1,1-diphenylphosphonitrilic fluoride trimer

The crystal structure of compounds with (N–P) n rings. VIII. Dichlorotetrakisisopropylaminocyclotriphosphazatriene hydrochloride, N3P3Cl2(NHPr i )4.HCl

“…In the segments P(1)-N(1)-P(2) and P(1)-N(3)-P(3), the difference in bond length (0.025 A) is related to the electronegativity of the substituents; the shorter P-N bonds are found on the side of the more electronegative substituents. This dependence of bond length on electronegativity has also been observed in the molecular structures of N3P3ClaPh4 (Mani, Ahmed & Barnes 1966), N3P3C14Ph2 (Man.i, Ahmed & Barnes, 1965 and N3P3F4Ph2 (Allen, Faught, Moeller & Paul, 1969). The P-N bonds in the segment P(2)-N(2)-P(3) are much longer than the other ring bonds, corresponding to the fact that this segment is phosphazane-like rather than phosphazene-like.…”

The molecular and electronic structure of 1-pyrazolylphosphazenes

“…The mean length of the exocyclic P-N bond (1.682 A) suggests some exocyclic conjugation. The mean ring bond length (1.577 A) is closer to the 1.58 1 A in N3P3C16 (35) than to the 1.605 A in N3P3Me6 (36) or 1.597 A in N3P3Ph6 (37), and the similarity of the structural effects of chlorine and the dimethylpyrazolyl group is confirmed by a comparison of the inequalities in the ring bonds of 6 , compared with those in N3P3Ph2C14 (38) and N3P3Ph2F4 (39). If methylation reduces electron withdrawal by the pyrazole group, the unsubstituted pyrazolyl group should be even more electronegative, in agreement with the structures of the two tetramers 4 and 5, which are compared with other tetramers in Table 3.…”

X-ray crystallography of the Cl3[N(CH3)2]P3N3compounds. I. Crystal structure of the geminal 2,2,4-trichloro-4,6,6-trisdimethylaminocyclotriphosphazatriene

“…The widest deviations from this value are observed in the N-P(C6Hh)2-N angles of Clz(C6Hh)4P3N 3 and (C6Hs)zCI4P3N3 by Mani, Ahmed & Barnes (1965, and of (C6Hs)zF4P3N3 by Allen, Moeller & Paul (1969), where they occur in the range I15"2-115"9 °. In the present structure, the N(I)-P(2)-N(3) and N(3)-P(4)-N(5) angles are 120.7 and 119.0 ° respectively, but the N(1)-P(6)-N(5) angle is only 113.1 °.…”