Metal-phosphide complexes

Heterometallic alkali metal phosphide complexes with transition metals have also been reported. The complex [(Cy2P)3Hf(ju.-PCy2)2Li (DME)] results from the reaction of LiPCy2 with HfCl4(THF) (98). This complex persists in solution. Jones et al. have reported the synthesis and reactivity toward a range of electrophiles of a series of lithium di-t-butylphosphido(alkyl)cuprates [RCu(PBu2)Li] (R = Me,... 

Figure 13 The structure of a range of metal-phosphide complexes...

One of the routes leading to P-stereogenic phosphines is electrophilic substim-tion at the phosphorus atom of secondary phosphines, as a result of asymmetric catalysis in which a catalyst activates a phosphorus nucleophile or a carbon electrophile, creating an asymmetric environment, i.e., creating preference for one of Si or Re face sides at the reactive center [103-113]. Upon reaction with chiral metal complexes, racemic secondary phosphines are converted into diaste-reomeric metal-phosphide complexes A or B, which interconvert rapidly through the inversion at phosphorus. If the equilibrium A B is faster than the reaction of A or B with an electrophile E, then P-stereogenic phosphines 196, in which pyramidal inversion is slow, can be formed enantioselectively. The product ratio in this dynamic kinetic asymmetric transformation depends both on and on the rate constants ks and (Scheme 63). 

Heteropolynudear phosphide complexes phosphorus as unique atom bridging coinage metal centers. Chemistry - A European Journal, 6(22), 4116-4123. 

The first heavier alkali metal phosphide species to be structurally characterized were the sodium and potassium complexes [M P(mes) (SiFBu2) (THF)2]2 (M = Na, K) (67). These isostructural complexes adopt an eight-membered (MPSiF)2 ring motif in which each alkali... 

Metal-phosphine complexes are ubiquitous in orgenometalljc chemistry. There are also metalhted phosphoranes (L M—PR ), phosphides (L M—PR2), end phosphimdenes (l. M—PR). Give specific examples of each. 

The phosphinidenequadricyclane was converted to phosphinidenenorbornadiene by treatment with HgCl2, while its treatment with CuCl2 led to a phosphaallene derivative (equation 86)111,112. Weber and coworkers have prepared phosphaalkenyl metal complexes by reaction of the metal carbonyl complexes with the silyl phosphide 11a (equation 87)113. 

The cleavage of a P-Ph bond (method (1)) has been widely used to create a variety of phospholide salts. Notably, this methodology has been employed in the synthesis of group 13 phospholyl complexes, which have come to the fore in recent years as potential single source substrates for the preparation of the corresponding metal phosphides by chemical vapor deposition (CVD). This is exemplified by the reaction of lithium 2,5-di(tert-butyl)phospholide with GaBr to afford a Ga(l) polymer 297 (Scheme 101) <1999AGE1646>. Additionally, this synthesis nicely illustrates the use of bulky substituents in the position a to phosphorus to favor -coordination. 

Route (4) for the preparation of phospholyl complexes, namely insertion of diynes into metal phosphide bonds and subsequent cyclization, is the least used approach. However, an alternative synthesis of299 and 300 using this type of methodology has been demonstrated successfully (Scbeme 105) <1996AGE1125>. 

A range of chelating phosphine ligands with small bite size have been shown to stabilize metal bonds. In addition to chelates, metal phosphide, amido, and even polyelemental derivatives exist. A range of truly novel complexes are known, such as the two products isolated in low yield in equation (29). The dimers retain metal-metal bonding and stabilize the coordinated P2 and 6 fragments. ... 

In terms of the total number of species known, the transition metals chemistry of phosphorus is dominated by the metal phosphides and by complexes of organo-substituted phosphanes. Both are dealt with in some detail in other sections suffice to say here that transition metal phosphane complexes are of paramount importance in terms of catalytic behavior in all manner of industrial and academic-related scenarios - and as such have been extensively reviewed. 

Asymmetric Synthesis by Homogeneous Catalysis Carbonyl Complexes of the Transition Metals Carbonylation Processes by Homogeneous Catalysis Heterogeneous Catalysis by Metals Phosphides Solid-state Chemistry Polynuclear OrganometaUic Cluster Complexes Zeolites. 

---