Intramolecular Aurophilic Interaction Research Articles

Theoretical study of the novel sandwich compound [Au3Cl3Tr2]2+

A theoretical study of a sandwich compound with a metal monolayer sheet between two aromatic ligands is presented. A full geometry optimization of the [Au(3)Cl(3)Tr(2)](2+) (1) compound, which is a triangular gold(I) monolayer sheet capped by chlorines and bounded to two cycloheptatrienyl (Tr) ligands was carried out using perturbation theory at the MP2 computational level and DFT. Compound (1) is in agreement with the 18-electron rule, the bonding nature in the complex may be interpreted from the donation interaction coming from the Tr rings to the Au array, and from the back-donation from the latter to the former. NICS calculations show a strong aromatic character in the gold monolayer sheet and Tr ligands; calculations done with HOMA, also report the same aromatic behavior on the cycloheptatrienyl fragments giving us an insight on the stability of (1). The Au -Au bond lengths indicate that an intramolecular aurophilic interaction among the Au(I) cations plays an important role in the bonding of the central metal sheet.

Highlights on the recent advances in gold chemistry—a photophysical perspective

The presence of inter- and/or intra-molecular aurophilic interactions among the closed-shell gold(I) centres in various systems has been studied from various aspects, including synthetic, spectroscopic and theoretical approaches. The employment of different ligands can impose a significant influence on these factors and give rise to new complexes with interesting structural and photophysical properties. In this tutorial review, a number of recent examples are selected to illustrate the fascinating properties and chemistry, as well as versatility of gold(I) in these aspects and their potential applications to newcomers in this field. An emerging class of luminescent gold(III) complexes is also described.

Mono- and Binuclear Gold(I) Amido Compounds of Purine Derivatives

Abstract A series of neutral dinuclear and mononuclear gold(I) complexes with phosphine and N-bonded 9H-purin-9-ate or 9H-purin-6-ylamine-9-ate have been synthesised under basic conditions and characterised by gHSQC, 1H,13C gHMQC and 1H detected 1H,15N gHMQC experiments in addition to ESI-MS and IR spectroscopy. Intermolecular aurophilic interactions are present in the structures of polymeric 1,2-bis(diphenylphosphine)ethane(9H-purin-9-ate)gold(I) 1, (3.1641(4) Å ) and 1,3- bis(diphenylphosphine)propane(9H-purin-9-ate)gold(I) 3, (3.52Å ). The N-Au-P angle in 1 is exceptionally small (166.3(1)°). Intramolecular aurophilic interaction (3.63 Å ) complemented by hydrogen bonding dictates the non-oligomeric structure of 1,3-bis(diphenylphosphine)propane(9H-purin- 6-ylamin-9-ate)gold(I) (7). Dimeric aurophilic interactions appear in the structure of (tributylphosphine)( 9H-purin-9-ate)gold(I) (11) (3.2311(7) Å ), while the structure in the other mononuclear compound, (triphenylphosphine)(9H-purin-9-ate)gold(I) (9) is organised by Au. . .N-interactions.

The Role of Secondary Interactions in Group 11 Metal Complexes Containing the Ferrocene Ligand FcCH2NHpyMe in Supramolecular Structures

AbstractThe ferrocene ligand 6‐[(ferrocenylmethyl)amino]‐2‐picoline, FcCH2NHpyMe [Fc = (η5‐C5H5)Fe(η5‐C5H4)], has been prepared by treatment of FcCH2NMe2 with 6‐amino‐2‐picoline, NH2pyMe. The coordination chemistry with group 11 metals has been studied and several complexes with coordination of the metal atom to the pyridine nitrogen atom, such as [M(PPh3)(FcCH2NHpyMe)]OTf, [Au(C6F5)(FcCH2NHpyMe)] and [AuR3(FcCH2NHpyMe)] (M = Au, Ag; R3 = (C6F5)3, (C6F5)2Cl; OTf = trifluoromethanesulfonate), have been obtained. The complex [Cu(FcCH2NHpyMe)2]PF6 has also been synthesised with a probable coordination of the copper centre to the pyridine and amine nitrogen atoms. Deprotonation of the NH group allows the synthesis of dinuclear complexes of the type [M2(PPh3)2(FcCH2NpyMe)]X or [Au2(C6F5)(PPh3)(FcCH2NpyMe)] with a mixed pyridine−amide ligand. Some of the complexes have been characterised by X‐ray diffraction and show the presence of intramolecular aurophilic interactions in the dinuclear complex and intermolecular interactions leading to chains in the mononuclear complex. Other types of secondary bonds are present in these structures, such as hydrogen bonding and weak η2 interactions between the gold centre and the cyclopentadienyl ring. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Theoretical study of the d 10–d 8 interaction between Au(I) and Au(III) on the cis/ trans-[PH 3Au(I)C(L)C(L)Au(III)(R) 2PH 3] (R=–H, –CH 3; L=–H, –CH 3) systems

We have carried out an ab initio study designed to shed some light on the aurophilic attractions between Au(I) and Au(III) in the [PH 3Au(I)C(L)C(L)Au(III)(R) 2PH 3] (where R=–H, –CH 3; L=–H, –CH 3) model. Calculations carried out at the MP2 level revealed important facts such as the presence of an intramolecular aurophilic interaction in the cis-complexes that stabilizes them with respect to the trans-isomers. Using two additional models to study the intermolecular interaction between Au(I) and Au(III) we were able to estimate an interaction energy between 21 and 25 kJ mol −1 at the MP2 level of calculation.

Luminescent gold(I) and silver(I) complexes of 2-(diphenylphosphino)-1-methylimidazole (dpim): characterization of a three-coordinate Au(I)-Ag(I) dimer with a short metal-metal separation.

The Au(I) and Ag(I) closed-shell metal dimers of 2-(diphenylphosphino)-1-methylimidazole, dpim, were investigated. dpim formed the discreet binuclear species [Ag2(dpim)2(CH3CN)2](2+) (1) when reacted with appropriate Ag(I) salts. Likewise, [Au2(dpim)2](2+) (3) and [AuAg(dpim)3](2+) (4) were produced via reactions with (tht)AuCl, tht is tetrahydrothiophene, and Ag(I). Compound 3 exhibits an intense blue luminescence (lambdamax=483 nm) in the solid state. However, upon initial formation of 3, a small impurity of Cl- was present giving rise to an orange emission (lambdamax=548 nm). Attempts to form [Au2(dpim)2]Cl2 yielded only (dpim)AuCl (2), which is not visibly emissive. The rare three-coordinate heterobimetallic complex [AuAg(dpim)3](2+) (4) exhibits intense luminescence in the solid-state resembling that of 3. The crystal structures of 1-4 were determined, revealing strong intramolecular aurophilic and argentophilic interactions in the dimeric compounds. Compound 1 has an Ag(I)-Ag(I) separation of 2.9932(9) A, while compound 3 has a Au(I)-Au(I) separation of 2.8174(10) A. Compound 4 represents the first example of a three-coordinate Au(I)-Ag(I) dimer and has a metal-metal separation of 2.8635(15) A. The linear Au(I) monomer, 2, has no intermolecular Au(I)-Au(I) interactions, with the closest separation greater than 6.8 A.

Syntheses and X-ray structures of mixed-metal gold phosphine clusters including an example having a highly asymmetric Re 2Au 2 skeleton

This study describes the synthesis and single crystal X-ray characterization of three new heteronuclear gold clusters, i.e. (OC) 5Re–Re(CO) 4Au 2dppfe ( 1), Au 4Co 2(CO) 7(PPh 3) 3 ( 2), and [Au–Co(CO) 4] 2( cis-dpen) ( 3). They were synthesized from reaction of (AuCl) 2dppfe with NaRe(CO) 5 at room temperature, reaction of (PPh 3)AuCl with NaCo(CO) 4, and reaction of (AuCl) 2-( cis-dpen) with NaCo(CO) 4, respectively. Compound 1 crystallizes in the monoclinic space group P2 1/ n with a=15.331(7), b=23.427(9), c=13.621(6) Å, β=112.53(3)° and Z=4. Compound 2 crystallizes in the triclinic space group P 1 ̄ with a=12.838(4), b=22.406(6), c=11.759(4) Å, α=103.15(2), β=117.06(2), γ=82.78(2)°, and Z=2. Compound 3 crystallizes in the triclinic space group P 1 ̄ with a=10.704(2), b=17.437(3), c=10.597(2) Å, α=96.73(2), β=108.02(2), γ=99.53(2)°, and Z=2. In 1, two gold atoms in the Au 2dppfe group are bound to one Re atom in the Re 2(CO) 9 group. Thus, the total skeleton is highly asymmetric. The metal skeleton of 2 is composed from a butterfly-like Au 4 backbone with a capping Co(CO) 3 group and the terminal Co(CO) 4 group coordinated to one Au atom. Two gold atoms come close in 3 to cause intramolecular aurophilic interaction. Terminal Co(CO) 4 groups in 2 make an intermolecular pair in a head-to-tail manner in the crystal.