Camphor-derived β-ketophosphonate complexes of molybdenum (VI ) and titanium (IV ); crystal and molecular structure of dichloro [(1R)-endo-(+)-3-(diethoxyphosphoryl)camphor]dioxomolybdenum(VI )
| Autor: | Raymond K. Mackie, David J. Cole-Hamilton, Michael Gahagan, Mary E. Harman, Michael B. Hursthouse, Domenico C. Cupertino |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | J. Chem. Soc., Dalton Trans.. :2195-2199 |
| ISSN: | 1364-5447 0300-9246 |
| DOI: | 10.1039/dt9900002195 |
| Popis: | Reaction of (1R)-endo-(+)-3-(diethoxyphosphoryl)camphor (L) with MoO2Cl2 gives [MoO2Cl2L] with cis oxygen and trans chloro ligands if the stoicheiometry is 1 : 1 whilst 2 equivalents of L give [MoO2Cl2L2]. On reaction with 1 equivalent of L, TiCl4 gives [TiCl4L]. The complexes were characterised by i.r., 1H, and 31P n.m.r. spectroscopy, and shown to contain bidentate binding (through the phosphoryl and carbonyl oxygen atoms) except for [MoO2Cl2L2], where binding is only through the phosphoryl oxygen. The compound [MoO2Cl2L] has been characterised crystallographically. Crystals are orthorhombic (space group P212121) with a= 15.528(2), b= 13.721(2), c= 9.777(1)A, and Z= 4. The structure was obtained from 1 664 observed intensities measured on a diffractometer and refined to an R value of 0.043. The complex is distorted octahedral about molybdenum with mutually cis oxygen atoms and mutually trans chlorine atoms although the O–Mo–O angle is 102.8 (5)° and the Cl–Mo–Cl angle is only 158.0(1)°. The organic ligand is bound through the phosphoryl and carbonyl oxygen atoms and the geometry of the ligand is little distorted from that of e.g. 3-bromocamphor. The bite angle for the bidentate ligand is 78.6 (3)° and the Mo–O (phosphoryl) bond length [2.183(7)A] is significantly shorter than to the cabonyl oxygen [2.402(7)A]. The known absolute configurations of the chiral centres have been confirmed as (1R), (3S), and (4S). |
| Databáze: | OpenAIRE |
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