Structure and conformation of bis(acetylacetonato)oxovanadium(IV) and bis(maltolato)oxovanadium(IV) in solution determined by electron nuclear double resonance spectroscopy.
Structure and conformation of bis(acetylacetonato)oxovanadium(IV) and bis(maltolato)oxovanadium(IV) in solution determined by electron nuclear double resonance spectroscopy.
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电子核双共振光谱测定溶液中双(乙酰丙酮)氧钒(IV)和双(麦芽糖)氧钒(IV)的结构和构象。
DOI：
10.1021/ic040120y
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Makinen,MarvinW
中科院分区：
文献类型：
--
作者：
Mustafi,Devkumar;Makinen,MarvinW
用电子核双共振(Endor)光谱测定了冰冻甲醇中双(乙酰丙酮)氧钒(IV)[VO(Acac)2]和双(麦芽)氧钒(IV)[VO(Malto)2]的结构和构象。内球和外球配位溶剂的位置由Endor通过使用选择性的氢化甲醇类似物来指定。类似地，VO(Acac)2的甲基和甲基芳基质子的共振特征也通过位置选择的氢气进行了鉴定。对于VO(AcAc)2，ENDOR确定的金属−质子距离最好由四方-金字塔几何构型的络合物解释，与X射线结晶学测定的结果基本相同[Dodge，R.P.；Templeton，D.H.；Zalkin，A.J.Chem。Phys.1961，35，55]，但与配位到钒氧的内球溶剂分子和轴向定位的溶剂分子氢键连接到钒氧上。与其在晶体中的转位构象相反[Caravan，P.；et al.J.Am化学。Soc.1995,117,12759]，发现VO(MALTO)2络合物以非构象形式存在，其中一个麦芽配体的给体氧原子占据了赤道配位。第二个麦芽糖配体的一个给体氧原子占据了与钒氧原子相对的轴向配位，另一个占据了赤道位置。还鉴定了赤道平面上的一个内球配位的甲醇分子和一个与钒氧氢键合的溶剂分子。没有观察到任何证据表明这是一种强迫症。
The structure and conformation of bis(acetylacetonato)oxovanadium(IV) [VO(acac)2] and bis(maltolato)oxovanadium(IV) [VO(malto)2] in frozen methanol have been determined by application of electron nuclear double resonance (ENDOR) spectroscopy. The positions of inner- and outer-sphere-coordinated solvent were assigned by ENDOR through use of selectively deuterated analogues of methanol. Similarly, the methyl and methylinyl proton resonance features of VO(acac)2were identified by site-selective deuteration. For VO(acac)2, the ENDOR-determined metal−proton distances were best accounted for by a complex of tetragonal-pyramidal geometry, essentially identical to that determined by X-ray crystallography [Dodge, R. P.; Templeton, D. H.; Zalkin, A.J. Chem. Phys.1961,35, 55] but with an inner-sphere solvent molecule coordinatedtransto the vanadyl oxygen and an axially positioned solvent molecule hydrogen-bonded to the vanadyl oxygen. In contrast to itstransconformation in crystals [Caravan, P.; et al.J. Am. Chem. Soc.1995,117, 12759], the VO(malto)2complex was found in acisconformation whereby the donor oxygen atoms of one maltolato ligand occupied equatorial coordination sites. One of the donor oxygen atoms of the second maltolato ligand occupied the axial coordination site opposite the vanadyl oxygen atom, and the other an equatorial position. An inner-sphere-coordinated methanol molecule in the equatorial plane and a solvent molecule hydrogen-bonded to the vanadyl oxygen were also identified. No evidence for thetransisomer was observed.