Homoleptic neutral complexe

Potentially coordinatively unsaturated dithiolene-metal complexes are rare,298-306 and 1 1 dithiolene-transition-metal complexes with no other ligands are, to our knowledge, unprecedented.307 The neutral complex [PdS2C2(COOMe)2]6,308 is homoleptic containing one dithiolene unit for each palladium atom and no other ligands. Electrochemical reduction of the compound depicted in Figue 21 proceeds in four reversible steps. 

Table 7.1 Calculated first BDEs De (Do) (kcal/mol) of neutral homoleptic carbonyl complexes. ...

Let us pass now to the wider class of homoleptic (tris)quinoidal complexes (already mentioned in Chapter 5, Section 1, speaking about the redox couple [V(cat)3]2 /3 ) starting with the neutral complex [Cr 02C6H2(3,S-Bu h], the essentially octahedral structure of which is shown in Figure 32.54... 

Like Cr, W is able to form a variety of neutral, mononuclear, homoleptic alkyl complexes, in this case in oxidation states as high as six. Treatment of WClg with only 3 equiv of LiMe in ethereal solution affords the (sometimes explosively) labile WMe. ... 

The synthesis of a neutral homoleptic uranium complex, URj. has finally been achieved.Why do you think R = [CH(SiMe2)jr was chosen for this synthesis ... 

Dinuclear complexes were obtained by reacting some binary copper(I) and silver(I) homoleptic pyrazolate complexes with neutral ligands. The trimeric [Cu(dmpz)]3 (23) readily reacted with phen or RNC (R = cyclohexyl) to give the doubly bridged species [(phen)Cu(/i-dmpz)2Cu(phen)], 32, (49) or [(RNC)Cu(/t-dmpz)2Cu(RNC)], 33 (50). The dimeric nature of 32 was argued from its spectroscopic and chemical properties, while 33 was characterized by an X-ray crystal structure analysis (50). 

Neutral homoleptic allyl complexes of lanthanoids apparently are not prepared till now. However, bimetallic complexes of the ar -type Li2Ln(r -C3H5)5(diox)n have been synthesized for most lanthanoids [3, 4, 5, 6, 7]. They are formed in the reaction of anhydrous trichlorides of lanthanoids with five equivalents of allyllithium ... 

Table 1 shows the calculated bond lengths of neutral homoleptic carbonyl complexes at the HF and MP2 levels of theory using basis set 11. Furthermore, DFT results using the BP86 functionals with two different basis sets are shown. One set of DFT calculations using BP86 used relativistic ECPs with TZ quality valence basis sets for the transition... 

There are two types of neutral complexes homoleptic and heteroleptic. The former are generally dimers, with two cadmium atoms penta-coordinated by two molecules of dithiocarbamate, which acts as an anisobidentate ligand (Figure 31). One sulfur atom from one of the molecules coordinated to the cadmium ion acts as a bridge to the other cadmium atom, bringing about a distorted square pyramidal coordination geometry with the axial position occupied by the bridging sulfur atom [117]. 

Hahde ligands are found in homoleptic complexes as well as in mixed ligands systems. HaUde complexes of Ir(IV) such as [IrCy [16918-91-5] are readily reduced to Ir(III) species, eg [IrCy [14648-50-1], in neutral or basic solution, or in the presence of reducing agents such as KI, oxalate, or photochemical activation (173). 

A number of general features in Table 1-3 is apparent. Complexes may be cationic, neutral or anionic. Ligands may be simple monatomic ions, or larger molecules or ions. Many ligands are found as related neutral and anionic species (for example, water, hydroxide and oxide). Complexes may contain all of the same type of ligand, in which case they are termed homoleptic, or they may contain a variety of ligand types, whereby they are described as heteroleptic. Some ligands such as nitrite or thiocyanate can coordinate to a metal ion in more than one way. This is described as ambidentate behaviour. In such cases, we commonly indicate... 

Most of the conducting or magnetic materials investigated in the homoleptic series are salts while many of the radical heteroleptic complexes described above are in their neutral state, potentially allowing for a stronger three-dimensional character. 

Since the discovery of hexacarbonylvanadium(O) and hexacarbonylvanadate( 1-) by Calderazzo and co-workers in 1959 and 1960, these substances have been key precursors to a variety of vanadium compounds, including inorganic noncarbonyl species, organovanadium complexes," and other vanadium carbonyls. Neutral V(CO)6 is of special interest in that it is the only isolable 17-electron homoleptic metal carbonyl and exhibits fascinating chemical properties that are often reminiscent of iodine and classic pseudohalogens. ... 

From Green to Red with Neutral Homoleptic Complexes. 157... 

Table 4 lists properties of the neutral homoleptic complexes with facial geometry, Ir(CAN)3, whose ligands are illustrated in Fig. 6 [35]. 

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