Polynuclear copper complexes

In the past ten years it is probably (ii) and (iii) above that have provided the major incentive in the synthesis of novel dimeric structures in copper(II) systems.30 Reference 10 includes a review of polynuclear copper(II) complexes in general and ref. 30 includes reference to a large range of biologically relevant dinuclear copper(II) complexes. The structural chemistry of binuclear copper(II) complexes was reviewed in 1977.586 In order to systematize the description of copper(II) polynuclear structures the following notation is introduced. 

Platinum complexes (continued) with aryls, thallium adducts, 3, 399 with bis(alkynyl), NLO properties, 12, 125 with bisalkynyl copper complexes, 2, 182-186 with bis(3,5-dichloro-2,4,6-trifluorophenyl), 8, 483 and C-F bond activation, 1, 743 in C-H bond alkenylations, 10, 225 in C-H bond electrophilic activation studies, 1, 707 with chromium, 5, 312 with copper, 2, 168 cyclometallated, for OLEDs, 12, 145 in diyne carbometallations, 10, 351-352 in ene-yne metathesis, 11, 273 in enyne skeletal reorganization, 11, 289 heteronuclear Pt isocyanides, 8, 431 inside metallodendrimers, 12, 400 kinetic studies, 1, 531 on metallodendrimer surfaces, 12, 391 mononuclear Pt(II) isocyanides, 8, 428 mononuclear Pt(0) isocyanides, 8, 424 overview, 8, 405-444 d -cP oxidative addition, PHIP, 1, 436 polynuclear Pt isocyanides, 8, 431 polynuclear Pt(0) isocyanides, 8, 425 Pt(I) isocyanides, 8, 425 Pt(IV) isocyanides, 8, 430... 

Recent research reveals that the oxidative polymerization of phenol with 02 also obeys the multielectron transfer with the polynuclear copper complexes [74], The multielectron oxidation of substrates provides new active species,... 

Copper complexes are known in oxidation states ranging from 0 to +4, although the +2 (cupric) and the +1 (cuprous) oxidation states are by far the most common, with the divalent state predominating. Only a relatively small number of Cu complexes have been characterized and the Cu° and oxidation states are extremely rare. A few mixed valence (see Mixed Valence Compounds) polynuclear species have also been isolated examples include a CuVCu species and a Cu /Cu catenane. The coordination numbers and geometries (see Coordination Numbers Geometries) of copper complexes vary with oxidation state. Thus, the majority of the characterized Cu complexes are square planar and diamagnetic, as is common for late transition metals with d electronic configurations. 

Cluster Compounds Inorganometalhc Compounds Containing Transition Metal Main Group Elements Copper Inorganic Coordination Chemistry DinuclearOrganometal-lic Cluster Complexes Polynuclear Organometalhc Cluster Complexes Silver Inorganic Coordination Chemistry. 

The hexaaza [ISJaneNe forms complexes with transition metal ions and with certain alkali and alkaline earth and lanthanide ions. For the higher aza macrocycles with seven or more donor atoms, dinuclear complexes become possible. A systematic investigation of both the structural and thermodynamic aspects of copper complexes formed with the larger polyaza macrocycles from heptaaza to dodecaaza has been published. All of the macrocycles were found to form hydroxo species as well as polynuclear complexes. A number of structures have been determined for the higher polyaza macrocycles, both in complexed and noncomplexed forms, and structures range from highly boat shaped to nearly planar. ... 

Two other copper complexes, mononnclear [Cn(acac)(phen)(H20)]C104 and onedimensional polynuclear [Cu(acac)(bipy)(C104)] , have square-pyramidal structure. The latter complex has fragments bridged by perchlorate anions resulting in nentral polynn-clear chains. The solid-state spectra exhibit a broad d-d band and intraligand tt-tt transitions. IR data show that C—O vibrations correspond to a very strong intensity band at 1585 cm , as well as 1578 and 1525 cm . ... 

On the basis of these observations and the known structures of a few polynuclear copper complexes, we suppose that CuC=CR is a part of a soluble complex, e.g. structure 26 . The coordination number of the copper is probably 4 and the ligands (L) may be amine, alkyne, etc. In the coupling reaction, the slow step is the release or transfer of X from carbon. These speculations lead to something like the progression in equation (271). 

Despite the short metal-metal distances in this tetramer, among the shortest for Cu, metal-metal bonding is rule out °. This underscores the difficulty in assessing the contribution of Cu-Cu interactions to the structure and chemistry of polynuclear copper complexes. 

In type IV, the thiolate sulfur atom coordinates to a metal atom and the thiocarbonyl sulfur coordinates to another metal atom. This type of coordination is seen in tetrathiooxalate complexes (see Sect.2.7) [21-30].This coordination style is also seen in polynuclear silver and copper complexes [31,32]. 

The suggested mechanisms of the various catalytic Click reactions involve the formation of dinuclear or tetranuclear copper complexes (162,163) as the catalyst (Fig. 11) and the creation of a Cu—C bond or a Cu=C bond in the intermediate species (49,121,122,162-166). DFT calculations were used to ascertain the relative stabilities of such complexes (163), showing that the mononuclear complex was more stable than the polynuclear complex. 

The hexanuclear platinum-copper complex Pt2Cu4(C6F5)4(C=C Bu)4(acetone)2] (320) and the polynuclear derivative [PtCu2(C6F5)2(C=CPh)2] c (321), which... 

A number of complexes of copper with 1,1-dithiolenes are known they are interesting, inasmuch as they form (1) polynuclear species, e.g., [Cu4(i-mnt)3]2 . Recently, a copper(III) complex of 1,1-dicarboeth-oxy-2-ethylenedithiolate (DED ) was prepared (375) by oxidation of aqueous solutions of K2[Cu(DED)2] with a 10-15% excess of Cu(II) or H202, and of (BzPh3P)2[Cu(DED)2] with I2. The possibility of this system as a model for the Cu "/Cu. system in n-galactose oxidase has been pointed out. Lewis and Miller (113) also prepared M[Cu(S2C CHN02)2] (M = Cu, or Zn) and Cu[Cu S2C C(CN)2 2], and found that they are effective insecticides. 

Amino acid is one of the most important biological ligands. Researches on the coordination of metal-amino acid complexes will help us better understand the complicated behavior of the active site in a metal enzyme. Up to now many Ln-amino acid complexes [50] and 1 1 or 1 2 transition metal-amino acid complexes [51] with the structural motifs of mononuclear entity or chain have been synthesized. Recently, a series of polynuclear lanthanide clusters with amino acid as a ligand were reported (most of them display a Ln404-cubane structural motif) [52]. It is also well known that amino acids are useful ligands for the construction of polynuclear copper clusters [53-56], Several studies on polynuclear transition metal clusters with amino acids as ligands, such as [C03] [57,58], [Co2Pt2] [59], [Zn6] [60], and [Fe ] [61] were also reported. 

A plethora of polynuclear copper(I) complexes with bi-, tri-, and tetracon-necting dithiophosphato ligands have been discovered. These include cyclic dimers, [CuS2P(OEt)2 PPh3]2,43 tetrahedral Cu4[S2P(OPr )2]4,44 prismatic Cu6 S2P(OR)2 6, cubane Cu8(p8-E )[S2P(OEt)2]6 (E = S, Se),45 (also known for silver)46 and [Cu8 S2P(OPr )6(p8-X)][PF6] (X = Cl, Br).47 A supramolecular chain-like array of cubane units interconnected through iodine bridges was found in Cu8(S)[S2P(OEt)2]6(p-I) x.48... 

Synthesis of copper and zinc complexes of 5,7-dimethyl-l,2,4-triazolo [l,5-a]pyrimidine has been reported [93AX(C)1902 94AX(C)510], Reaction of copper(II) thiocyanate with 5,7-dimethyl-l,2,4-triazolo[l,5-a]-pyrimidine (l) gave three different complexes two isomers of [Cu(NCS)2L2]2 and Cu(NCS)2L2 H20 (84IC2803). The mononuclear complexes, bis(thiocyanato-N)bis(6-methyl-l,2,4-triazolo[l,5-a]pyrimidine-jV-3)copper(II) and the polynuclear pseudo-layered complexes, bis(thio-cyanato-A0bis(5-methyl-l,2,4-triazolo[l,5-a]pyrimidine-A -3)copper(II) were prepared (89POL2313). 

---