π-Acid/π-Base Carbonyloxomolybdenum(IV) Complexes and Their Oxomolybdenum(VI/IV) Precursors
π-Acid/π-Base Carbonyloxomolybdenum(IV) Complexes and Their Oxomolybdenum(VI/IV) Precursors
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π-酸/π-基羰基氧钼(IV)配合物及其氧钼(VI/IV)前体
DOI：
10.1021/ic0510314
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发表时间：
2006
影响因子：
4.6
通讯作者：
C. G. Young
中科院分区：
文献类型：
--
作者：
M. S. Malarek;David J Evans;P. D. Smith;Ashley R. Bleeker;J. White;C. G. Young
TpiPrMoO(SR)(NCMe)与CO气体在甲苯中反应生成棕色TpiPrMoO(SR)(CO)(TpiPr=氢化三(3-异丙基吡唑-1-基)硼酸酯；R=Et，IPR，Ph，p-tol，BZ)。碳氧钼(IV)配合物的ν(CO)和ν(MoO)红外吸收峰分别位于2025和935 cm-1左右，核磁共振谱具有C1对称性，δC(CO)约为250。TpiPrMoO(SiPR)(CO)的晶体结构为扭曲的八面体构型，d(MoO)=1.683(3)A，d(Mo−C)=2.043(5)A，∠(OMO−C)=90.87(16)°。蓝绿色的乙腈前驱体是由顺-TpiPrMoO2(SR)与PPh3反应生成的，它们是不稳定的，在约950 cm-1处显示单一的ν(MoO)红外光谱，核磁共振谱符合C1对称性。红棕色顺式TpiPrMoO2(SR)(R=如上，TbU)是由TpiPrMoO2Cl和HSR/NEt3在二氯甲烷中歧化生成的。配合物的ν(MoO_2)红外光谱在925和895 cm~(-1)处有较强的吸收峰，核磁共振谱显示Cs的对称性；
Brown TpiPrMoO(SR)(CO) (TpiPr = hydrotris(3-isopropylpyrazol-1-yl)borate; R = Et, iPr, Ph, p-tol, Bz) are formed when TpiPrMoO(SR)(NCMe) react with CO gas in toluene. The carbonyloxomolybdenum(IV) complexes exhibit ν(CO) and ν(MoO) IR bands at ca. 2025 and 935 cm-1, respectively, and NMR spectra indicative of C1 symmetry, with δC(CO) ca. 250. The crystal structure of TpiPrMoO(SiPr)(CO), the first for a mononuclear carbonyloxomolybdenum complex, revealed a distorted octahedral geometry, with d(MoO) = 1.683(3) A, d(Mo−C) = 2.043(5) A, and ∠(OMo−C) = 90.87(16)°. The blue-green acetonitrile precursors are generated by reacting cis-TpiPrMoO2(SR) with PPh3; they are unstable, display a single ν(MoO) IR band at ca. 950 cm-1, and exhibit NMR spectra consistent with C1 symmetry. Red-brown cis-TpiPrMoO2(SR) (R = as above and tBu) are formed by metathesis of TpiPrMoO2Cl and HSR/NEt3 in dichloromethane. The complexes exhibit strong ν(MoO2) IR bands at ca. 925 and 895 cm-1, and NMR spectra indicative of Cs symmetry; t...