Mixed-ligand preparation

The procedure described here is not limited to the preparation of polymers such as 2. Starting from the difunctional silane 3 we have synthesized a copolymer, poly(dimethyl-co-isocyanopropylmethyl-siloxane) > as well as a linear homopolymer, poly(isocyanopropyl-methylsiloxane) 8 (Scheme 2). Indeed, preparation of a monofunctional analogue of 2. and h creates the potential for end-capping with an isocyanide function any polymer containing other functional groups, thereby in principle permitting mixed ligand complexes of polymers to be accessed. 

Pidgeon, C. Ong, S. Choi, H. Liu, H., Preparation of mixed ligand immobilized artificial membranes for predicting drug binding to membranes, Anal. Chem. 66, 2701-2709 (1994). 

In contrast with the Schiff base salen, salicylaldehyde oxime (79) (salox) complexes of Co have received comparatively little attention, but a series of bis-bidentate divalent complexes of the form iraiis-Co(sa 1 ox)2( D M SO)2 have been reported.343 The heterocyclic bidentate oxime violurate (lH,3H-pyrimidine-2,4,5,6-tetrone 5-oximate, Hvi) (80) and its /V-methyl (mvi) and /V,/V -dimethyl (dmvi) derivatives form high-spin divalent [Co(vi)]+ and Co(vi)2 complexes, whereas [Co(vi)3] is low spin.344 The mixed-ligand Co(dmvi)2(phen) complex is also low spin. The crystal structure of m-Co(pxo)2Br2 (pxo = 2-acetylpyridine-l-oxide oxime) is isostructural with the Ni11 relative.345 The dichloro complex also adopts a cis configuration. The tridentate dioximes 2,6-diformyl-4-methylphenol dioxime and 2,6-diacetyl-4-methylphenol dioxime (Hdampo) form binuclear complexes of the type (81a) and (81b) respectively.346 Cobalt oxide nanoparticles were prepared by... 

Various thiourea ligands have been used in the synthesis of mixed ligand complexes. A series of complexes [NiQ2L2] (HQ = ethylacetoacetate, L = thiourea, allyl-, benzoyl-, methyl-, diphenyl-thiourea) have been prepared. The complexes are all paramagnetic (/i = 3.02-3.27/iB) and have been assigned tra 5-octahedral structures.1014... 

A series of mixed-ligand thiosalicylato complexes of the type PtL(PPh3)Y2] (Y2 = thiosalicylate L = pyridine, 4-methylpyridine, picolinic acid hydrazide, imidazole) have been prepared by the reaction of [PtCl2(COD)] with PPh3, thiosalicylic acid, and A-donor ligand in MeOH solution.375 The X-ray structure of the pyridine derivative (162) was determined, the first example of where a platinum atom is coordinated to a N, O, P, and S donor atom set. 

The versatility of the [TcN]2+ core is indicated by the preparation of a wide variety of mixed-ligand complexes. TcN 02S2 coordination is represented by... 

Mohammad Jafar Soltanian Fard-Jahromi and Ali Morsali (2010) Sonochemical synthesis of nanoscale mixed-ligands lead(II) coordination polymers as precursors for preparation of Pb2(S04)0 and PbO nanoparticles thermal, structural and X-ray powder diffraction studies. Ultrason Sonochem 17(2) 435-440... 

The preparation of chlorine derivatives is carried out in a more convenient way using PhICl2 instead of Cl2 gas, as demonstrated for the mixed-ligand auracycles with R = Me, Et (Equation (35)).184... 

Subsequently, Lowenthal and co-workers,3 la,9 Evans et al.,31b and Muller et al.98 reported chiral bis(oxazoline) ligands 185, 186, and 83 as shown in Figure 5-12. The gem-dimethyl [(bis)oxazoline] 83-coordinated copper catalyst is the most widely used ligand. The catalyst is prepared in situ by mixing ligand 83 with an equal molar amount of CuOTf. Asymmetric cyclopropanation of isobutylene with ethyl diazoacetate (EDA) gives ethyl 2,3-dimethylcyclopro-pane carboxylate with >99% ee. 

An exhaustive treatment of the electrochemical behaviour of transition metal complexes is beyond the scope of this book, because the enormous number of ligands available, combined with the possibility to prepare mono- and/or polynuclear complexes using identical or mixed ligands, would render such a task almost impossible. Therefore, the discussion is limited to some aspects associated with the redox properties of (essentially) mononuclear metal complexes. In particular, we will concentrate representatively on the redox changes of first row transition metal complexes (excluding the metallocene complexes, as they have been already discussed in Chapter 4) that give stable, or relatively stable products. A systematic and useful examination of the redox activity of organometallic complexes of transition metals dated to 1984 has appeared.1... 

Fe(CO)s], [Fe2(CO)g], [Co2(CO)8] and [Os3(CO)i2]) have been reacted with dicyanobenzene to form intrazeolite [M(Pc)] complexes [140]. Another class of materials prepared by the intrazeolite template synthesis method has been mixed ligand metal carbonyls and metal carbonyl clusters, frequently by reductive car-bonylation of metal ions in zeolite cages [175]. However, because these are frequently decomposed in situ to form, for example, nanoparticles, they are outside the scope of this chapter, and will be considered here only when they are used as precursors for metal complexes. 

Since complexes of this mixed-ligand type play an important role in the development of receptorbinding radiopharmaceuticals,attention was paid to the preparation of pure mixed-ligand complexes with Tc. The preparation of [ TcO(SSS)(SR)j at the n.c.a. level in good yield and purity is possible only by subsequent HPLC separation of the mixture. " ... 

A number of neutral mixed-ligand oxorhenium(V) complexes containing tridentate [SC2H4YC2Lt4S] (Y = S,0) (95) and monodentate, monoanionic thiolate ligands have been prepared from [ReOCU] and a mixture of the ligands (Scheme The intermediate... 

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