Pentanuclear species

We describe herein its conversion into the tetranuclear cluster anion [Co3Ru(CO)12] itself leading to the pentanuclear species Co3RuCu(CH3CN)(CO)12 in good yield. 

Figure 10.79 X-ray molecular structures of cyclic helicates (a) pentanuclear species formed from 10.124 and templated by Cl 87 (b) hexanuclear species formed from 10.126 and templated by C104 (reproduced by permission of The Royal Society of Chemistry).

Fe4N(CO)i2] and [Fe5N(CO)i4]" (90). After 1 hour at 130 C the tetranuclear cluster is isolated in 3.3% yield, while the pentanuclear species, which forms after longer reaction times (2 hours) at a slightly higher temperature (145 C), is produced in 66% yield. This anion could be protonated and the structure of HFesN(CO)i4 is shown in 22. It was noted that below 130°C a nitrosyl complex was formed. 

With zirconium the hexanuclear molecule [(IVO)4(/i3-OPr )2(/r-OPr )Zr2(iU,-0Pr )2Ba(/i-0Pr )2Ba(/i-0Pr )2Zr2(/r3-0Pr )2(/r-0 )(0 )4] was obtained, with six-coordinated metals. The confacial bi-octahedral Zr2(OlV)9 units act as tetradentate bridging groups to each barium." The pentanuclear species piaZr4(OPr )i8] has a similar strucmre to that of piaTi4(OEt)i8]. 

The comparison of Tables 4.17 and 4.18 shows some significative differences in the species described in them. As exemplified with the species Pbs" mentioned above, there are species that appear to be stable only in either solution or in the solid state. In the case of many polyanions with relatively high charge as the anions described by Zintl M3" (M = As, Sb, or Bi) and M5" (M = As or Bi), the demands in solvent dielectric constants and the stability to reduction of both solvent and counterions appear to be higher than those found until now. Although polyanion Pbg" was the first to be discovered its stabilization in the solid state is still not possible. All experiments lead to the pentanuclear species Pbs" mentioned above, probably due to the comproportionation reaction. 

The heterometallic ketenyl complexes [0s3W(//-H) G(0)GH2 (G0)3Gp ] (Gp = Gp or Gp ) that possess a pendant Gp W(GO)3 substituent were prepared by the condensation of [Os3(GO)io(NGMe)2] with the metal-aldehyde complex [Gp W(GO)3GH2GHO]. Pyrolysis of these ketenyl complexes in the solid state at 185 °G afforded tetra-nuclear clusters in the case of the Gp derivative, whereas the Gp system gave pentanuclear species.In both cases, G-O bond scission in the ligated ketene fragment was observed. 

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