hosphorus-nitrogen compounds Part 51 : the relationship between spectroscopic and crystallographic data of mono- and di-spirocyclophosphazene derivatives with 4-fluoro/nitrophenylmethyl pendant arm/arms

Authors : Aytuğ OKUMUŞ, Gamze ELMAS, Nuran ASMAFİLİZ, Selen Bilge KOÇAK, Zeynel KILIÇ

Pages : 559-573

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A great wealth of structural information about phosphazenes can be gleaned from the combined spectroscopic and crystallographic data. When data from $^{31}$P NMR spectroscopy and X-ray crystallography are put together like pieces in a puzzle, a number of correlations can be obtained for phosphazene derivatives. A systematic study concerning the correlations among the structural parameters e.g., $^{31}$P NMR data, endocyclic/exocyclic NPN bond angles and bond lengths revealed some characteristics of mono- and di-spirocyclophosphazene derivatives bearing~4-fluoro/nitrophenylmethyl pendant arm/arms. These correlations include the relationship between the $\delta $P$_{spiro}$ shifts, the values of electron density transfer parameters $\Delta $ P--N , and the endocyclic and exocyclic NPN bond angles of the cyclophosphazenes. The structural parameters were compared with each other for 19 compounds of 5 different architectural types of cyclophosphazenes with 5- to 7-membered spiro-rings.
Keywords : spiroCyclophosphazene, 4 fluoro nitrophenylmethyl pendant arm, ^ 31 P NMR, X ray crystallography, electron density transfer parameter