Isocyanide ligands halides

Examples in organocopper chemistry are the synthesis of h -cyclopentadienyl-copper complexes with phosphite, phosphine or isocyanide ligands via the reaction of h -CjHjTl with Cu(I) halide-ligand complexes in pentane or THE at 25°C . 

Morgenstem DA, Ferrence GM, Washington J, Henderson JI, Rosenhein L, Heise JD, Fanwick PE, Kubiak CP (1996) A class of halide-supported trinuclear nickel clusters PMi3(m3-L)(m3-X) (m2-dppm)3]n-i-(L = I-, Br-, CO, CNR X = I-, Br- n = 0,l dppm = Ph2PCH2PPh2) novel physical properties and the fermi resonance of symmetric m3-hl bound isocyanide ligands. J Am Chem Soc 118 2198-2207... 

Reaction of [Pt3(/u-S02)3 P(Cy)3 3] with 2,6-xylyl isocyanide results in displacement of one or at most two of the S02 ligands by the isocyanide.21 Similarly, carbon monoxide usually only partially displaces the S02, but the addition of trimethylamine /V-oxide (Me3NO) facilitates the substitution leading to formation of [PtsQx-COjsfPlCyjs js].22 Me3NO also facilitates substitution of one S02 ligand by halides and azide.2... 

Lever has successfully predicted Mn"/ potentials of 24 Mn-carbonyl complexes containing halide, pseudohalide, isonitrile, and phosphine co-ligands, with additivity parameters derived from the potentials of Ru "/" couples [39]. An important consideration for heteroleptic complexes is the influence of isomerism on redox thermodynamics. For Mn(CO) (CNR)6- complexes, with n = 2 or 3, the Mn"/ potentials for cis/trans and fac/mer pairs differ by as much as 0.2 V [40]. The effect arises from the different a-donor and 7r-acceptor abilities of carbonyl (CO) and isocyanide and their influence on the energy of the highest energy occupied molecular orbital (HOMO). 

Complexes with the simplest alkoxyphenylisocyanide and several halides are prepared by metathetical reactions of [AuCl(CNR)] with KX salts (Figure 7.19) [17]. The chloro-derivatives (n > 4) andthebromo-complexes (n > 6) display SmA phases. However, the ligands and the iodo-complexes are not liquid crystals. The transition temperatures decrease in the order Cl > Br > I, according to the decrease in polarity of the Au—X bond. It is important to note that the coordination of a very simple non-mesomorphic isocyanide (only one alkoxy chain and one aromatic ring) to Au—Cl allows the formation of a quite ordered and stable smectic mesophase. 

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