硅烷基五羰基锰(CO)_5MnSiR_3的光化学合成

Photochemical Syntheses of Silyl Manganese Pentacarbonyls (CO)_5MnSiR_3

对甲基苄基五羰基锰[(CO)5Mn-p-CH2C6H4CH3,4a]或对甲氧基五羰基锰[(CO)5Mn-p-CH2C6H4OCH3,4b]与1～2当量R3SiH的C6H6或C6D6溶液在5℃光解,经色谱纯化后得到中等或高收率硅烷基五羰基锰(CO)5MnSiR3;SiR3=SiMe2Ph(1b),SiMePh2(1c),SiPh3(1d),SiHPh2(1e),SiEt3(1f),SiMe2-t-Bu(1g)和SiMe2Et(1h).光化学反应后,对二甲苯和对甲基苯甲醚副产物分别定量生成,并伴随少量Mn2(CO)10(<1%～6%).色谱柱的尺寸和温度(室温至-65℃)的选择视初始浓度的分解,色谱柱展开期间1的稳定性(过载),以及1与Mn2(CO)10的分离难易而定.去除Mn2(CO)10后的硅烷基五羰基锰1b～1g为浅黄色油状物或无色晶体(只有1h无法分离得到纯净物).尽管这些化合物对空气敏感对热却相对稳定.

Photolysis of para-methyl benzyl manganese pentacarbonyl [（CO）5Mn-p-CH2C6H4CH3, 4a] and para-methoxy benzyl manganese pentaearbonyl [（CO）5Mn-p-CH2C6H4OCH3, 4b] with 1-2 equivalents of R3SiH in C6H6 or C6D6 at 5℃ yielded the silyl manganese pentacarbonyls （CO）5MnSiR3; SiR3=SiMe2Ph （1b）, SiMePh2 （1c）, SiPh3 （1d）, SiHPh2 （1e）, SiEt3 （1f）, SiMe2-t-Bu （1g）, and SiMe2Et （1h） in moderate to high yields after chromatographic purification. Quantitative production of respective byproducts p-xylene and p-methylanisole, along with variable yields of Mn2（CO）10 （〈 1% to 6%） was observed after the photochemical reaction. Conditions for the chromatographic isolation differed for each product. Choice of column size and temperature （room temperature to -65 ℃） was made according to initial concentration-dependent decomposition （overloading）, stability during development and separability of 1 with Mn2（CO）10. Once freed from Mn2（CO）10 1b-1g were isolated as pale yellow oil or off white crystals （only lh was not isolated purely）. Although very air sensitive these products are otherwise stable thermally.