Linear Heterotrinuclear Complex Research Articles

Linear CuI2 Pd0 , CuI Pd02 , and AgI2 Pd0 Metal Chains Supported by Rigid N,N'-Diphosphanyl N-Heterocyclic Carbene Ligands and Metallophilic Interactions.

Selective copper(I) to palladium(0) transmetallation of P-donors from the rigid N,N'-diphosphanyl-imidazol-2-ylidene C3 H2 [NP(tBu)2 ]2 (PCNHC P) was observed when known [Cu3 (μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)3 was reacted with [Pd(PPh3 )4 ]. When 1.2 equivalents of [Pd(PPh3 )4 ] was used, the product [Cu2 Pd(μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)2 (2(OTf)2 ) was obtained, which features a CuI -CuI -Pd0 chain and appears to be the first linear heterotrinuclear complex with d10 -d10 interactions between Pd0 and CuI . When the Cu3 precursor was reacted with 3.0 equivalents of [Pd(PPh3 )4 ], the complex [CuPd2 (μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)2 (3(OTf)2 ) was obtained, which, on the basis of magnetic measurements, DFT calculations, and computed nuclear shieldings, was formulated as containing a Pd0 -CuI -Pd0 chain with an electron hole delocalized over the whole cation, including the metal chain. Similarly, selective transmetallation of the P-donors in [Ag3 (μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)3 from silver to palladium (originating from [Pd(PPh3 )4 ]) gave the linear chain [Ag2 Pd(μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)2 (5(OTf)2 ), which on the basis of NMR spectroscopy comprises an AgI -AgI -Pd0 metal core. However, X-ray diffraction data collected on various samples of 5(OTf)2 were modeled with 50:50 metal disorder at the terminal positions, corresponding to a (AgI /Pd0 )-AgI -(AgI /Pd0 ) formulation. Upon standing in solution, 5(OTf)2 transformed to 6(OTf)2 , the regioisomer of 5(OTf)2 in which the Pd center has migrated to the central position of an AgI -Pd0 -AgI chain. Prolonged standing in CH2 Cl2 or by reaction with [PtCl2 (NCMe)2 ] converts complex 6(OTf)2 to the AgI /PdII complex [Ag2 PdCl2 (μ3 -PCNHC P,κP,κCNHC ,κP)2 ](OTf)2 (7(OTf)2 ). The structural data of 2(OTf)2 , 3(OTf)2 , and 7(OTf)2 establish significant heterometallophilic interactions.

Linear heterotrinuclear complexes derived from an alkyl platinum(II) twelve-membered macrocycle.

The P,N,P-tridentate ligand 2,6-bis(diphenylphosphino)pyridine, L, was employed to generate a twelve-membered metallomacrocyclic host species cis-Pt(2)Me(4)(mu-L)(2) that encapsulates Tl(I) and Cu(I) guest ions. The ligand was also used to synthesize another two linear heterotrinuclear complexes, [Me(2)Pt(mu-L)(2)Ag(2)(MeCN)(2)](BF(4))(2).MeCN and [(CO)(3)Fe(mu-L)(2)Ag(2)(Et(2)O)](ClO(4))(2), both containing a metal-metal dative bond (Pt-->Ag and Fe-->Ag, respectively) and stabilized by the d(10)-d(10) argentophilic interaction.

On the rational synthesis and properties of exchange-coupled heterotrinuclear systems containing [MAMBMB] and [MAMBMC] cores †

Six new modular linear heterotrinuclear complexes of the types [MAMBMB] and [MAMBMC] with FeIIICuIINiII1, FeIIINiIINiII2, CoIIICuIINiII3, FeIIICuIICuII4, FeIIINiIICuII5 and FeIIIMnIICuII6 cores were synthesized using selective template reactions involving the ligands 1,4,7-trimethyl-1,4,7-triazacyclononane, tmtacn, and N,N′-bis(2-hydroxy-3-hydroxyiminomethyl-5-methylphenylmethylene)-1,3-propanediamine, H4Lox. The complexes were characterised by elemental analysis (C, H, N, and the metals), IR, UV-vis, Mössbauer and EPR spectroscopies and variable temperature and variable field magnetic susceptibility measurements. The crystal structure of 2 was determined by X-ray diffraction. It is comparable to those of the previously published compounds 1 and 3 and consists of high-spin FeIII and six-co-ordinated NiII embedded in the imine–oxime ligand, with an intramolecular Fe⋯Ni distance of 3.79 Å and Ni⋯Ni distance of 3.14 Å. The magnetic behaviour of the compounds is complex and exhibits a predominant antiferromagnetic exchange coupling acting along the pathway dx2 − y2∥sp2∥dx2 − y2∥sp2∥dx2 − y2. The coupling constant JMA-MB ranges from −5 to −20 cm−1, while JMB-MC ranges from −66 to −395 cm−1 (except for JNi-Ni = −21 cm−1). The coupling constant JMA-MC was kept fixed to zero during the fitting procedure. Compounds 1 and 5 with isoelectronic structures exhibit ground and first excited states inverted to one another due to their spin topology.

Bis[μ-N,N'-bis(salicylidene)-1,3-propanediaminato]bis(dimethylformamide)di(μ-nitrito)copper(II)dinickel(II)–Dimethylformamide (1/2)

The unit cell of the title compound, [CuNi2(NO2)2(C17H16N2O2)2(C3H7NO)2].2C3H7NO, contains two molecules of the linear heterotrinuclear complex and four solvent molecules. The central CuII ion and the terminal NiII ions have distorted octahedral coordination spheres. The Cu–Ni pairs are each triply bridged, by the O atoms of an N,N'-bis(salicylidene)-1,3-propanediaminato (salpd2−) ligand and by an O and an N atom of a nitrite group. The central CuII ion, located on an inversion centre, has a total of six O atoms in its coordination sphere: two from each salpd2− ligand and one from each bridging nitrite group. The NiII ions are related by the inversion centre and each is coordinated by the two O and two N atoms of a salpd2− ligand and one N atom from a nitrite and an O atom from a dimethylformamide (dmf) ligand. The dmf and nitrite groups are mutually trans about the NiII ion. The Cu—Ni distance is 2.9967 (4) Å.

A rational assembly of a series of exchange coupled linear heterotrinuclear complexes of the type MAMBMC as exemplified by FeIIICuIINiII, FeIIINiIICuII and CoIIICuIINiII

A general approach for the rational synthesis of linear trinuclear complexes containing three different metals MAMBMC is described and a member of the series, FeIIICuIINiII, has been characterized by X-ray crystallography and magnetic susceptibility measurements.

A novel series of heterotrinuclear complexes with a tris(dimethylglyoximato)metal(II) anion as bridging ligand. Structure of the FeIIICuIIFeIIIcomplex with S= 9/2 ground state

A series of linear heterotrinuclear complexes with a tris(dimethylglyoximato) metal(II) as bridging ligand, [LFeIII{µ-(dmg)3MII}FeIIIL](ClO4)2(M = Zn, Cu, Ni, Co, Fe, Mn), where L represents the cyclic triamine 1,4,7-trimethyl-1,4,7-triazacyclononane, has been synthesized and characterized by X-ray crystallography and magnetic susceptibility measurements.