苹果酸钼外消旋体的合成、光谱性质和结构表征  

Synthesis and Spectroscopic and Structural Characterization of Racemic Ammonium Dimeric(malato)dioxomolybdenum

作　　者：颜文斌[1] 周朝晖[2] 章慧[2] 万惠霖[2] 蔡启瑞[2] 

机构地区：[1]吉首大学化学系,吉首416000 [2]厦门大学化学系,厦门361005

出　　处：《高等学校化学学报》2001年第12期1967-1970,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 99330 40 );高等学校骨干教师资助计划;博士学科点基金资助

摘　　要：钼酸铵和外消旋苹果酸溶液反应得到外消旋苹果酸钼 ( )配合物 ,( NH4) 4[Mo∧ O2 ( S,S-Hmal) 2 ]·[MoΔO2 ( R,R-Hmal) 2 ],对该配合物进行了元素分析、电导测定、旋光和红外光谱表征 ,并测定了晶体结构 .该化合物晶体属单斜晶系 ,P2 1 / a空间群 ,晶胞参数 :a=0 .80 61 ( 2 ) nm,b=1 .32 86( 2 ) nm,c=1 .32 32 ( 2 ) nm,β=91 .80 ( 2 )°,V=1 .4 1 64( 9) nm3,Z=2 ,Dc=2 .0 0 8g· cm- 3 ,F( 0 0 0 ) =864,μ=9.70cm- 1 ,一致性因子 R=0 .0 5 1 ,Rw=0 .0 5 8.在该单核配合物阴离子中 ,钼上的两个苹果酸配体具有相同手性 ,它以α-烷氧基和α-羧基双齿配位形成畸变的八面体构型 。The complex (NH\-4)\-4\[Mo\-\{\%∧\%\}O\-2(\%S,S\%\|Hmal)\-2\]·\[Mo\-\{\%Δ\%\}O\-2(\%R,R\%\|Hmal)\-2\] was prepared from the reaction of ammonium molybdate and \%R,S\%\|malic acid at pH=2\_3. It was characterized by elementary analysis, conductivity measurement, optical rotation, IR and X\|ray diffraction. The complex crystallizes in monoclinic space group \%P\%2\-1/\%a\% with unit cell parameters: \%a\%=0.806 1(2) nm, \%b\%=1.328 6(2) nm, \%c\%=\{1.323 2(2) nm\}, \%β\%=91.82(2)°, \%V\%=1.416 4(9) nm\+3, \%Z\%=2, \%D\%\-c=2.008 g·cm\+\{-3\}, \%F\%(000)=864, \%μ\%=\{9.700 cm\+\{-1\}\} for 1 902 reflections with \%I\%≥3\%σ\%(\%I\%). The molybdenum atom is coordinated by two bidentate homochiral malic acid in distorted octahedron, while the \%β\%\|carboxyl groups remain uncomplexed. The crystal contains two isolated monomeric malatomolybdates(Ⅵ) anions in the configurations of \%∧\|S,S\% and \%Δ\|R,R\%. The two enantiomeric anions result in the formation of racemic compound. There is no evidence for the other diastereoisomers like (NH\-4)\-2\[Mo\-\{\%∧\%\}O\-2(\%R,S\%\|Hmal)\-2\], (NH\-4)\-2\[Mo\-\{\%Δ\%\}O\-2(\%R,S\%\|Hmal)\-2\], (NH\-4)\-2\[Mo\-\{\%∧\%\}O\-2(\%R,R\%\|Hmal)\-2\] and (NH\-4)\-2\[Mo\-\{\%Δ\%\}O\-2(\%S,S\%\|Hmal)\-2\] in this experiment.

关 键 词：苹果酸 苹果酸盐 钼(Ⅵ)配合物 固氮酶 晶体结构 合成 光谱性质 结构表征 

分 类 号：Q554.9[生物学—生物化学] O614.612[理学—无机化学]