Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo, 33071 Oviedo, Spain.
Inorg Chem. 2010 Dec 20;49(24):11595-605. doi: 10.1021/ic101839k. Epub 2010 Nov 17.
The anionic oxophosphinidene complexes (H-DBU)[MCp{P(O)R*}(CO)(2)] (M = Mo, W; R* = 2,4,6-C(6)H(2)(t)Bu(3); Cp = η(5)-C(5)H(5), DBU = 1,8-diazabicyclo [5.4.0] undec-7-ene) displayed multisite reactivity when faced with different electrophilic reagents. The reactions with the group 14 organochloride compounds ER(4-x)Cl(x) (E = Si, Ge, Sn, Pb) led to either phosphide-like, oxophosphinidene-bridged derivatives [MCp{P(OE')R*}(CO)(2)] (E' = SiMe(3), SiPh(3), GePh(3), GeMe(2)Cl) or to terminal oxophosphinidene complexes [MCp{P(O)R*}(CO)(2)(E')] (E' = SnPh(3), SnPh(2)Cl, PbPh(3); Mo-Pb = 2.8845(4) Å for the MoPb compound). A particular situation was found in the reaction with SnMe(3)Cl, this giving a product existing in both tautomeric forms, with the phosphide-like complex [MCp{P(OSnMe(3))R*}(CO)(2)] prevailing at room temperature and the tautomer [MCp{P(O)R*}(CO)(2)(SnMe(3))] being the unique species present below 203 K in dichloromethane solution. The title anions also showed a multisite behavior when reacting with transition-metal based electrophiles. Thus, the reactions with the complexes [M'Cp(2)Cl(2)] (M' = Ti, Zr) gave phosphide-like derivatives [MCp{P(OM')R*}(CO)(2)] (M = Mo, M' = TiCp(2)Cl, ZrCp(2)Cl; M = W, M' = ZrCp(2)Cl), displaying a bridging κ(1),κ(1)-P,O- oxophosphinidene ligand connecting MCp(CO)(2) and M'Cp(2)Cl metal fragments (W-P = 2.233(1) Å, O-Zr = 2.016(4) Å for the WZr compound]. In contrast, the reactions with the complex [AuCl{P(p-tol)(3)}] gave the metal-metal bonded derivatives trans-[MCp{P(O)R*}(CO)(2){AuP(p-tol)(3)}] (M = Mo, W; Mo-Au = 2.7071(7) Å). From all the above results it was concluded that the terminal oxophosphinidene complexes are preferentially formed under conditions of orbital control, while charge-controlled reactions tend to give derivatives with the electrophilic fragment bound to the oxygen atom of the oxophosphinidene ligand (phosphide-like, oxophosphinidene-bridged derivatives).
阴离子膦亚氮配合物（H-DBU）[MCp{P（O）R*}（CO）（2）]（M=Mo，W；R*=2,4,6-C（6）H（2）（t）Bu（3）；Cp=η（5）-C（5）H（5），DBU=1,8-二氮杂双环[5.4.0]十一-7-烯）在面对不同的亲电试剂时表现出多部位反应性。与第 14 族有机氯化合物 ER（4-x）Cl（x）（E=Si，Ge，Sn，Pb）的反应导致类似膦的，氧膦亚氮桥接衍生物[MCp{P（OE'）R*}（CO）（2）]（E'=SiMe（3），SiPh（3），GePh（3），GeMe（2）Cl）或末端氧膦亚氮配合物[MCp{P（O）R*}（CO）（2）（E'）]（E'=SnPh（3），SnPh（2）Cl，PbPh（3）；Mo-Pb=2.8845（4）Å对于 MoPb 化合物）。在与 SnMe（3）Cl 的反应中发现了一种特殊情况，该反应生成了两种互变异构形式的产物，其中类似膦的配合物[MCp{P（OSnMe（3））R*}（CO）（2）]在室温下占优势，而互变异构体[MCp{P（O）R*}（CO）（2）（SnMe（3））]是在二氯甲烷溶液中低于 203 K 时存在的唯一物种。标题阴离子在与基于过渡金属的亲电试剂反应时也表现出多部位行为。因此，与配合物[M'Cp（2）Cl（2）]（M'=Ti，Zr）的反应得到类似膦的衍生物[MCp{P（OM'）R*}（CO）（2）]（M=Mo，M'=TiCp（2）Cl，ZrCp（2）Cl；M=W，M'=ZrCp（2）Cl），显示出连接 MCp（CO）（2）和 M'Cp（2）Cl 金属片段的桥接κ（1），κ（1）-P，O-氧膦亚氮配体（W-P=2.233（1）Å，O-Zr=2.016（4）Å对于 WZr 化合物）。相比之下，与配合物[AuCl{P（p-tol）（3）}]的反应得到金属-金属键合衍生物反式-[MCp{P（O）R*}（CO）（2）{AuP（p-tol）（3）}]（M=Mo，W；Mo-Au=2.7071（7）Å）。从所有上述结果可以得出结论，在轨道控制条件下优先形成末端氧膦亚氮配合物，而电荷控制反应倾向于生成与氧膦亚氮配体的氧原子结合的亲电片段的衍生物（类似膦的，氧膦亚氮桥接衍生物）。
