Nitrogen–Phosphorus(III)–Chalcogen Macrocycles for the Synthesis of Polynuclear Silver(I) Sandwich Complexes

The synthesis of
inorganic N–P­(III)-Ch-based macrocycles
[−PhP–NMe–PPh–Ch−]2 (8Ch; Ch = S, Se) is presented by incorporating
two nitrogen, two chalcogen, and four phosphorus atoms. The macrocycles
are conveniently obtained via the cyclocondensation reaction of Na2Ch (Ch = S, Se) with the acyclic dichlorodiphosphazane ClPhP–NMe–PClPh
(9). Treatment with elemental sulfur (S8)
or gray selenium (Segray) results in an oxidative ring
contraction to give 1,3,2,4-thiazadiphosphetidine 2,4-disulfide (10S) and 1,3,2,4-selenazadiphosphetidine
2,4-diselenide (10Se), respectively.
Macrocycles 8Ch are excellent
multidentate ligands for transition metal complexation, as demonstrated
by the isolation of mono-, di- tri-, and tetranuclear silver sandwich
complexes. The polynuclear silver complexes are comprehensively characterized,
including detailed NMR and X-ray analysis.

本研究报道了无机N-P(III)-硫族元素基大环[−PhP–NMe–PPh–Ch−]₂（8Ch，Ch = S、Se）的合成，该类大环包含两个氮原子、两个硫族原子与四个磷原子。目标大环可通过Na₂Ch（Ch = S、Se）与无环二氯二磷氮烷ClPhP–NMe–PClPh（9）的环缩合反应便捷制备。将大环8Ch分别与单质硫（S₈）或灰硒（Se_gray）反应，可通过氧化环收缩过程分别得到1,3,2,4-噻二二磷杂环丁烷2,4-二硫化物（10S）与1,3,2,4-硒二磷杂环丁烷2,4-二硒化物（10Se）。大环8Ch是性能优异的多齿配体，可用于过渡金属配位，该结论可通过单核、双核、三核及四核银三明治配合物的分离得到验证。该系列多核银配合物已得到全面表征，包括详细的核磁共振（NMR）与X射线分析。