Group IVB

Group IVB.—A survey of their reactions with electrophiles suggests that organo— tin-transition-metal complexes may be regarded as pseudohalides aliphatic C—Sn bonds are deactivated, and aromatic C—Sn bonds activated. Transition- 

Futnagalli, S. Martinengo, P. Chini, A. Albinati, S. Bruckner, and B. T. Heaton, 

Group IVB.—[TiCp2Cl(SiMe3)] has been structurally characterized and the related cyclometallopolysilane complex, [TiCpa(SiPh2)4], prepared.  

Permethylcyclopentasilane/Fe derivatives have been prepared and a skew-boat configuration is adopted by 1,3,5-trisilacyclohexane when complexed to iron.  

Preparative routes to [Co(CO)n(SiR3)L ] (R=F, n= —3 R=Ph, OEt, n=l,Z L=PR3, AsRs) have been described together with a variety of 5-and 6-co-ordinate silyl-iridium(iii) complexes.  

A -Ray studies have established the structure of [ClSn Fe(CO)2Cp 2 Co-(00)4 ] and the electrochemical reduction of [Fe(CO)2CpX] (X=SnCl3, GeClg) has been studied and shown to proceed in two 1-e steps. The reaction of [W(CO)5 Ge(Smesityl)2 ]BX3 gives [ W(CO)5 2(/M-GeX2)] (X= Cl, Br) and a variety of Mn and Co derivatives of di- and tri-germane have been prepared.  

Insertion of [PtCPPhglg] into a Bi-Ge bond occurs on reaction with [BiOu-GeR2)3Bi] (R=C6Fs).  

4 Group IVB.- Of the numerous derivatives incorporating Si or Ge bonds to transition metals, structurally interesting molecules reported in 1984 include [HSi Pe(C0)LCp CO2(y-CO)(CO)3)3 with a ferrio-silanediyl unit bridging a Co-Co bond, CCOg (yg-Si) (y-CO)j (CO) 

In L0s3Sn(vi-HK CH(SiMe2) 2 2 10 there is a closed planar 0S3Sn 

Very little is known about chalcogenide halides of Group IVB elements. Although the existence of sulfide chlorides (45, 274, 329, 365) and of a selenide chloride (329) of titanium was claimed in early publications, their true composition, and even their existence, remains doubtful. They have usually been obtained by the reaction of titanium chlorides with sulfur and selenium, respectively, or with hydrogen sulfide. The synthesis of a pure compound, TiSCl2, was published in 1959 (113). It is an intermediate of the reaction of TiCU with H2S. 

An optimal reaction-temperature of 65°C was claimed. The blackish brown TiSCU is very sensitive to oxygen and humidity. As no X-ray measurements have been made, additional work is needed. Titanium sulfide halides have also been claimed as catalysts for the polymerization of propylene (363). 

Nothing has thus far been reported concerning chalcogenide halides of other elements of Group IVB. 

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The fundamental Ziegler-Natta recipe consists of two components the halide or some other compound of a transition metal from among the group IVB to VIIIB elements and an organometallic compound of a representative metal from groups lA to IIIA. Some of the transition metal compounds that have been... 

Previous studies of the hydrothermal hydrolysis of tetravalent Th, U and Np (1-4) have shown a remarkable similarity in the behavior of these elements. In each case compounds of stoichiometry M(0H)2S0i, represent the major product. In order to extend our knowledge of the hydrolytic behavior of the actinides and to elucidate similarities and differences among this group of elements, we have investigated the behavior of tetravalent plutonium under similar conditions. The relationships between the major product of the hydrothermal hydrolysis of Pu(IV), Pu2(OH)2(SO.,)3 (H20) t, (I)> and other tetravalent actinide, lanthanide and Group IVB hydroxysulfates are the subject of this re-... 

Group IVB, actinide, and lanthanide, hydrothermal hydrolysis spectroscopic studies. 58-62... 

Group IVB, actinide and lanthanide hydrothermal hydrolysis (continued)... 

Transition Metal Complexes with Group IVB Elements J. F. Young... 

Compounds Li[R3EE R3], with group-IIIB-group-IVB bonds are accessible from ER3 (E = Al, Ga, In, Tl R = Me, Ph) combined with LiE R3 (E = Si, Ge, Sn) polysubstituted forms, e.g., Li[MenTl(SnMe3)4 n] (n = 0-3), can also be obtained . Side reactions yield Sn2Meg, ascribed to disproportionation ... 

Compounds of the type E(IXE(III)R2] that are analogous to the group-IA-group-IVB compounds, e.g., LiSnPh3, should be given by dehalogenation of diorganometal halides ... 

Transition metal complexes with Group IVB elements 241... 

Organometallic complexes containing Group IIIB and Group IVB ligands 115a... 

Silicon-transition metal chemistry is a relatively new area. The work of Hein and his associates (1941) on Sn—Co derivatives established the possibility of forming bonds between a Group IVB metal and a transition element 139), but it was another fifteen years before CpFe(CO)2SiMej 203), the first of many silyl derivatives, was synthesized. The interest in these compounds derives from (1) comparison with the corresponding alkyl- and Ge-, Sn-, and Pb- transition metal (M) complexes, including the role of ir-back-bonding from filled d orbitals of M into empty d orbitals on Si (or other Group IVB metal), and (2) expectation of useful catalytic properties from such heteronuclear derivatives. 

The compound [Cl2SiFe(CO)4]2 is obtained from Fe(CO)j and HSiClj, in a sealed tube reaction (148). It is presumably a member of the family of Group IVB-iron metallocycles of structural type (XI) (40, 246). Two Ni... 

Lukevits, E. Y., and Voronkov, M. G., Organic Insertion Reactions of Group IVB Elements (transl. M. J. Newlands). Consultants Bureau, New York, 1966. 

E. H. Brooks and Organometal. Chem. Group IVB metal derivatives of the 56 ... 

T. R. Crompton, Chemical Analysis of Organometallic Compounds. Volume 3. Elements of Group IVB, Academic Press, London, 1974, pp. 1-12. 

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