COMPLEXES WITH UNBRIDGED DATIVE BONDS BETWEEN OSMIUM AND A GROUP-6 ELEMENT - STRUCTURES OF (ME3P)(OC)4OSCR, (ME3P)(OC)4OSW(CO)5
COMPLEXES WITH UNBRIDGED DATIVE BONDS BETWEEN OSMIUM AND A GROUP-6 ELEMENT - STRUCTURES OF (ME3P)(OC)4OSCR, (ME3P)(OC)4OSW(CO)5
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DOI：
10.1021/om00106a026
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发表时间：
1989-04-01
期刊：
影响因子：
2.8
通讯作者：
RUSHMAN, P
中科院分区：
文献类型：
--
作者：
DAVIS, HB;EINSTEIN, FWB;RUSHMAN, P
（R3P）（OC）4OsM（CO）5（R= Me、OMe、Ph等;以Os（CO）_4（PR_3）和M（CO）_5（THF）为原料，在正己烷中反应，合成了一系列金属配合物（M= Cr，Mo，W）。用X射线单晶衍射法测定了（Me_3 P）（OC）_4OsCr（CO）_5（1）和（Me_3 P）（OC）_4OsW（CO）_5（2）的晶体结构：化合物1属P_2i/n空间群，a= 9.231（1）A，B= 18.153（1）A，c= 10.865（1）A，A = 91.08（1），Z= 4;对1748个反射面，R= 0.023，Rv= 0.028。化合物2以空间群P21/n结晶，其中a= 8.832（1）A，B= 16.241（2）A，c= 12.988（2）A，λ = 101.99（1），并且Z= 4;对于2189个观察到的反射，R= 0.019，Rw= 0.023。在1和2中，Os（CO）4（PMe 3）分子通过非桥连的给体-受体金属-金属键（Os-Cr= 2.9787（14）A; Os-W= 3.0756（5）A）作为M（CO）6片段的配体;膦配体反式到金属-金属键。（R3 P）（OC）4 OsM（CO）5配合物的主要光谱特征表明它们在溶液中具有相同的结构。然而，在13 C（和31 P）NMR光谱中有微弱的信号，这与少量的具有磷配体顺式金属-金属键的异构体一致。对于2，异构体被证明是在快速平衡的自旋饱和转移技术。涉及金属原子之间的成对羰基交换的众所周知的机制解释了关于异构化的观察结果。还制备了均配型衍生物（OC）_5OsCr（CO）_6。虽然在室温下在溶液中不稳定，但CD 2Cl 2在-40 ℃下的13 C NMR谱表明它也具有非桥连Os-Cr配价键的结构。
Complexes of the type (R3P)(OC) 4OsM (CO) 5 (R= Me, OMe, Ph, etc.; M= Cr, Mo, W) have been prepared from the reaction of Os (CO) 4 (PR3) and M (CO) 5 (THF) in hexane. The structures of (Me3P)(OC) 4OsCr (CO) 5 (1) and (Me3P)(OC) 4OsW (CO) 5 (2) have been determined by X-ray crystallography: Compound 1 crystallizes in the space group P2i/n, with a= 9.231 (1) Á, b= 18.153 (1) A, c= 10.865 (1) Á, ß= 91.08 (1), and Z= 4; R= 0.023, Rv= 0.028 for 1748 observedreflections. Compound 2 crystallizes in the space group P21/n, with a= 8.832 (1) A, b= 16.241 (2) A, c= 12.988 (2) A, ß= 101.99 (1), and Z= 4; R= 0.019, Rw= 0.023 for 2189 observed reflections. In both 1 and 2 the Os (CO) 4 (PMe3) molecule acts as a ligand to the M (CO) 6 fragment via an unbridged donor-acceptor metal-metal bond (Os-Cr= 2.9787 (14) A; Os-W= 3.0756 (5) A); the phosphine ligand is trans to the metal-metal bond. The major spectroscopic features of the (R3P)(OC) 4OsM (CO) 5 complexes indicate these compoundsadopt the same structure in solution. There are, however, weak signals in the 13C (and and 31P) NMR spectra that are consistent with small amounts of the isomer with the phosphorus ligand cis tothe metal-metal bond. For 2, the isomers were shown to be in rapid equilibrium by the spin saturation transfer technique. The well-known mechanism that involves pairwise carbonyl exchange between metal atoms accounts for the observations regarding the isomerization. The homoleptic derivative (OC) 5OsCr (CO) 6 has also been prepared. Although unstable in solution at room temperature, the 13C NMR spectrum in CD2C12 at-40 C indicates it also has a structure with an unbridged, Os-Cr dative bond.