Determınatıon Of Absolute Confıguratıon Of 8,8,10,10tetrachloro-20,21-Dıhydro-18h,23h-6,12-Epıazeno-6λ5,8λ5,10λ5, 12λ5[1,3,2]Benzoxazaphosphonıno[2',3':8,9][1,3,5,7,9,2,4,6,8] Pentaazatetraphosphacycloundsyno[2,1-B][1,3,2] Benzoxazaphosphonıne Usıng X-Ray Crystallography
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Date
2019-12-31
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Ankara Üniversitesi Fen Fakültesi
Abstract
The title compound, 8, 8, 10, 10-tetrachloro-20,21-dihydro-18H, 23H-6, 12epiazeno-6λ5, 8λ5, 10λ5, 12λ5-[1,3,2] benzoxazaphosphonino [2',3':8,9][1,3,5,7,9,2,4,6,8] pentaazatetraphosphacyclo undsyno [2,1-b] [1,3,2] benzoxazaphosphonine; C16H16Cl4N6O2P4, a cyclotetraphosphazene, has a tetrachloro-2, 4-spiro-ansa-spiro (tetrachloro-2,4-sas) architecture in which the bicyclic structure has consisted of eightmembered tetrameric N4P4 and seven-membered ansa (N1/P1/P1′/N4′/C8′/C8/N4) rings fused with a common PNP fragment. The asymmetric unit possesses one-half of the molecule. P1 and P1′ atoms are stereogenic centres. In addition, there is a mirror plane passing through the N3 and N1 atoms in the molecule, and therefore, this compound is in meso form (RS/SR). According to the checkcif result, it is found that the absolute configuration of P1 and/or P1′ phosphorus centers is RS, displaying that in the solid-state there is only one enantiomer in the unit cell. The space group is P bnm with cell parameters of a = 6.2692(2), b = 15.8111(3), c = 22.9393(4) Å.
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Cyclotetraphosphazene, Spiro-ansa-spiro-Structure, X-ray crystallography