A new regioselective method of macrobicyclic Schiff bases synthesis

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• 作者：Rafal Kruszynski ; Mariola Siwy ; Iwona Porwolik-Czomperlik and Agata Trzesowska
• 关键词：Lariat ethers ; Spirocyclisation ; Crystal structure ; NBO
• 刊名：Inorganica Chimica Acta
• 出版年：2006
• 出版时间：20 January 2006
• 年：2006
• 卷：359
• 期：2
• 页码：649-658
• 全文大小：238 K

文摘

A new regioselective method of di-gem-thio-substituted PNP-crown derivatives synthesis is presented. The geminalmercaptoethanolanetricyclophosphaza-PNP-lariat ether structure has been determined by X-ray crystallography and characterised by ab initio calculations. The 16-membered PNP-crown ether ring exists in unique conformation: ac⁻ ap ac⁻ sc⁺ sc⁺ ap sc⁺ ap ap sc⁻ ap sc⁻ sc⁻ ac⁺ ap ac⁺. All the ether oxygen atoms are directed into the interior of the ring. All endocyclic P–N bond lengths are equal within experimental error with the mean value 1.578(2) . The P–S bond properties have been characterised in terms of natural bond orbital (NBO) analysis, and its interactions with other NBO have been described. The spirocyclisation mechanism at cyclophosphazene phosphorus atom has been proposed.