A systematic study is reported of the products of the nucleophilic substitution reactions of the spermine-bridged cyclotriphosphazene, [N3P3
X
4(NHCH2CH2CH2N)CH2CH2]2 [where X = Cl (2a)], to give a number of new structures [(2b)–(2g)] in which X = OPh, [spiro-O(CH2)3O]0.5, Ph, NHPh, NC4H8 and NHBu
t
, respectively. A comparison has been made between the sum of the substituent basicity constants, Σα
R
, obtained in nitrobenzene solution, and ten molecular parameters of the N3P3 ring (the internal bond angles α, β, γ, δ and θ, and the P—N bond lengths a, b, c, d and e) as well as the difference between the bond lengths a and b, Δ(P—N). It is found that the systematic change in molecular parameters of compounds (2a)–(2g) is in line with changes in α
R
values, indicating the similarity in relative electron-releasing capacity of substituents X in the solid state and in solution. It is also found that the effect on molecular parameters of (2a)–(2g) with two X substituents in PX
2 groups is greater than that for one X substituent in P(OR)X groups in an analogous series of compounds observed previously [Beşli et al. (2002). Acta Cryst. B58, 1067–1073].
本报告系统地研究了与精胺连接的环三唑磷的亲核取代反应产物[N3P3
X
4(NHCH2CH2CH2N)CH2CH2]2[其中 X = Cl (2a)]的亲核取代反应产物,得到了一些新结构[(2b)-(2g)],其中 X = OPh、[螺-O(CH2)3O]0.5、Ph、NHPh、NC4H8 和 NHBu
t
和 NHBu t。比较了取代基碱性常数 Σα
R
和 N3P3 环的十个分子参数(内键角 α、β、γ、δ 和 θ 以及 P-N 键长度 a、b、c、d 和 e)以及键长度 a 和 b 之间的差值 Δ(P-N))进行了比较。研究发现,化合物 (2a)-(2g) 分子参数的系统变化与 α
R
值的变化一致,这表明取代基 X 在固态和溶液中的相对电子释放能力相似。研究还发现,PX 2 基团中含有两个 X 取代基的 (2a)-(2g) 对分子参数的影响大于含有一个 X 取代基的 (2a)-(2g) 对分子参数的影响。
B58, 1067-1073]。