Homoleptic complexes synthesis

Scheme 8.1 Three key methods of the synthesis of lanthanide(lll) bis(phthalocyanine) complexes. Homoleptic complexes symmetrical (A, B) and unsymmetrical (C1 and C2, D1). Thereby, the thermal fusion group A can be subdivided into (A1) solvent free fusion (A2) refluxing in the mixture of protic solvents in the presence of organic base - DBU and (A3) MW assisted fusion.

Plummer, D.T. and Angelici, R.J. (1983) Synthesis and characterization of homoleptic complexes of the chelating bidentate isocyano ligand tert-BuDiNC. Inorg. Chem., 22, 4063. 

Homoleptic dialkyl iron complexes, synthesis and reactivity,... 

Homoleptic tetrazincates, characteristics, 2, 346 Homoleptic titanium(III) complexes, with -ligands, 4, 282 Homoleptic trizincates, characteristics, 2, 345 Homoleptic vanadium(III) alkyl complexes synthesis and structure, 5, 12 VMes3 reactivity, 5, 12... 

Probably the best-known pentanuclear organogold complex is the homoleptic complex [Au(p-mes)]5, whose synthesis by reaction of [AuCl(CO)] with the appropriate Grignard reagent in tetrahydrofuran solution [Eq. (50)] was first reported in 1983 by Floriani.143 An alternative synthetic procedure that takes place with precipitation of insoluble byproducts and uses a mesitylgold(I) derivative as a starting material [Eq. (51)] has been described more recently.31... 

Shen and coworkers used Kawaguchi s phenoxy functionalised carbene ligand for the preparation of nickel(II) [62] and iron (II) [63] carbene complexes. Using the same deprotonation method — NaN(SiMe3)2— they attempted the synthesis of a mono-carbene nickel(II) complex that resulted in the formation of the homoleptic complex instead [62] (see Figure 4.16). Use of the correct stoichiometries significantly increased the yield. 

Atypical synthesis of naAed NHC-containing complexes has been reported by Cloke and coworkers. As shown in equation (7), the co-condensation of nickel, paUadium, and platinum vapor with the free NHC, TBu, provided two-coordinated homoleptic complexes of Ni(0), Pd(0), and Pt(0) (43). Unfortunately, in addition to the poor yield of the isolated product, this original methodology required a metal vapor synthesis apparatus. 

The synthesis, structure, and physical and chemical properties of organo-lanthanide complexes containing only polyhaptocyclopentadienyl and cyclooctatetraenyl metal-carbon bonds are fully covered in other reviews (5-7). This section will focus on lanthanide-carbon single bonded species only. Ln—C single bonds are found almost exclusively in only two types of complexes homoleptic complexes, and heteroleptic... 

Numerous examples of homoleptic complexes in high or low formal oxidation states are known. In general, the high oxidation state complexes are best prepared by chemical or electrochemical oxidation of the normal oxidation state compounds, followed by further reaction in situ or precipitation with a suitable inert anion. In this respect, perchlorate is ideal as both oxidant and precipitant, but the complexes obtained are frequently violently explosive. Similarly, the low oxidation state complexes are best obtained by chemical or electrochemical reduction of available compounds (or normal oxidation salts in the presence of an excess of bpy). Commonly used reductants have included dissolving metals (zinc, sodium, lithium, magnesium) and the complexes Li(bpy) and Li2(bpy). Isolated examples are known of the synthesis of low oxidation state complexes by reaction of M(0) complexes with bpy or by metal vapor synthesis. 

In 1998, Kempe and coworkers [34] reported the first aminopyridinato rare-earth metal complexes. 4-Methyl-2-[(trimethylsilyl)amino]pyridine(HLl) was utilized in this complex. The reaction of lithiated LI and YCI3 in ether and pyridine led to the ate complex [Y(Ll)4(LiPy)] (Py = pyridine) (1). The complex 1 catalytically mediated a ligand transfer reaction to form [Pd(Ll)2] and [Y(Ll)3(py)] (2) from [Pd(cod)Cl2] (cod = cyclooctadiene). The LI ligand transfer from yttrium to palladium and the regeneration of 1 are significant in the efficient synthesis of the very strained amido palladium complexes (Scheme 2). Lithiated LI underwent a salt metathesis reaction with ScCb, at low temperature in THF, to yield the homoleptic complex [Sc(L1)3] (3) (Scheme 2). 3 is the first reported scandium aminopyridinato complex [35]. 

FIGURE 3.6 A picture of (U-mesityl)Au 5. (Data from A homoleptic arylgold(I) complex synthesis and structure of pentanuclear mesitylgold(I). S. Gambarotta, C. Floriani, A. Chiesi-Villa, and C. Guastini, Chem. Commun., 1983, 1304.)... 

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