Structural investigations of phosphorus–nitrogen compounds. 1. The structures of three monospiro compounds: N₃P₃[O(CH₂)₂O]Cl₄, N₃P₃[O(CH₂)₃O]Cl₄ and N₃P₃[O(CH₂)₄O]Cl₄. The relationship of OPO bond angles in PO₂N₂ tetrahedra with ³¹P chemical shifts

Structural investigations of phosphorus–nitrogen compounds. 2. The structures of N3P3(NH2)2Cl4, N3P3(NPPh3)(NH2)Cl4 and N3P3(NPPh3)Cl5 and a comparison with other phosphazenylphosphazenes. The relationship of conformation in the solid state to conformation in solution

“…A(P-N) =0.053 (3)/~. This type of bond variation was first observed by Mani, Ahmed & Barnes (1965) and has been previously discussed (Contractor, Hursthouse, Shaw, Shaw & Yilmaz, 1985). The mean P-C1 bond length is 1-996 (1)/~.…”

“…The adjacent angles, P(6)-N(1)-P(2) and P(4)-N(3)-P(2), in (4) are anomalously small (119.0 °) owing lo the bending of P(2) by 0.53 A out of the plane of P(6)-N(1)-N(3)-P(4). If we compare the difference, A(P-N) (Contractor, Hursthouse, Shaw, Shaw & Yilmaz, 1985) between RR'P-N [R = R'= NH2 (1), NHBu' (6); R = NH2, R'= NPPh3 (2); R = R'= NPPh3 (4)] and N-PC12 of the same P-N-P segment, we note an increase in the A(P-N) values i_n the non-hydrogen-bonded segments, 0.07 (1) A (6), 0.075 (4) ,~ (2) and 0.094 (7)/~, (4), and in the hydrogen-bonded segments, 0.04 (1)/~, (6), 0.053 (3) A (1), 0.087 (4)/~ (2), in line with the increasing electron release from the substituents R and R'. The mean P-CI bond lengths (attached to the non-hydrogen-bonded segments) increase in the same order 1.997 (3) <2.002 (1) <2.021 (2) A for compounds (6), (2) and (4) respectively, again demonstrating the increasing electron release.…”

The first substitution reactions of N,N-spiro bridged octachlorobiscyclotriphosphazene

“…Although the bond lengths and bond angles of the cyclotriphosphazene rings, (PN) 3 , of all compounds (2-6) are found within the normal range for many cyclotriphosphazenes [38][39][40], there are small differences in the P-N bond lengths and N-P-N bond angles because of the substitution by the 1,2-ethanedioxy moiety.…”

Synthesis and spectroscopic properties of geminal-bis(tertbutylamino) phosphazenes obtained by the reaction of spiro and ansa phenoxyphosphazenes with the tert-butylamine and the crystal structure of 2,2-[2,2’-metheylenebis(4-chlorophenoxy)]-4,4-bis(tert-butylamino)-6,6-dichlorocyclo- 2λ5,4λ5,6λ5-triphosphazatriene

“…However when R is a difunctional bulky substituent 24 or contains different substituents, the P-N bonds may show significant variations. 25,26 In the structure 3, the P-N bond lengths vary between 1.547(4) and 1.632(5) Å due to the influence of the difunctional bulky substituent and the tert-butylamino group. According to the earlier report of Allcock et al, 12 the P-O bond lengths are not unusual, however the P1A-O1 (1.542(4)] and the P1B-O2 [1.493(8)) bond lengths are shorter than P-O single bonds of 1.577(2) and 1.61 Å.…”