Jiaxi Lu

Assembly of silver(I) polymers with helical and lamellar structures

The new versatile multidentate nonchelating ligand 1,2-bis[(2-pyr-imidinyl)-sulfanylmethyl]benzene (bpsb) was designed and prepared for supramolecular syntheses. Self-assembly between silver nitrate and the bpsb ligand resulted in the polymer [Ag4(bpsb)2-(NO3)4]n (1) with a single-stranded helical chain structure. Each bpsb ligand in 1 acts as a tetradentate ligand, in which two sulfur atoms and two nitrogen atoms from different pyrimidine groups coordinate to four Ag atoms in four different directions. The nitrate anions serve as a template for the formation of the helix and are either embedded in the interior of the helix or located in the flank of the helix. Self-assembly between silver perchlorate and the bpsb ligand under the same conditions gave rise to the polymer [Ag2(bpsb)3(ClO4)2]n (2) comprising a two-dimensional lamellar network containing crownlike cavities. The silver atoms in two adjacent layers are arranged staggered in 2. The two-dimensional lamellar network comprising isolated cavities of [Ag6(bpsb)6] is very different from that of usual honeycomb structures.

The synthesis and crystal structure of a novel cubane-like molybdenum copper sulfur cluster [Mo3CuS4]·[S2P(OC2H5)2]3·I·CH3COO·HCON(CH3)2

Abstract The synthesis and crystal structure of a novel cubane-like cluster with a [Mo3CuS4] cluster core is reported herein. This compound was prepared from CuI upon reaction with the trinuclear molybdenum cluster {Mo3S4[S2P(OC2H5)2]4}·H20. The title compound crystallizes in a triclinic space group P 1 with the following unit cell dimensions: a= 12.639(3); b=13.722(2); c=14.644(2); α= 108.78(1); β=106.36(1); γ=102.54(1)°; Z=2; V=2124 ,A3; Dc=2.022 g cm−3. 7491 independent reflections were collected on a CAD-4 four-circle diffractometer with Mo Kα radiation in the range 1°

The synthesis and crystal structure of a cubane-like tungsten copper sulfur cluster [W3CuS4]· [S2P(OC2H5)2]3·I·μ2-CH3COO· C5H5N

The title compound crystallizes in the monoclinic space group P21/n with the following unit cell dimensions: a=14.196(3), b=17.203(3), c=18.075(3) A, β=86.02(2)°, Z=4, V=4404 A3, Dc= 2.358 g cm−3. 9235 independent reflections were collected on a CAD-4 four-circle diffractometer with Mo Kα radiation in the range 1°<θ<25°, with 5515 reflections having intensities within the range I⩾ 3σ(I). The structure was determined by direct methods and refined by the least-squares method to a final R index of 0.048. There are some distortions in the cubane-like [W3CuS4] core, with three WW bonds and three weak WCu bonds.

A novel polymeric silver(I) complex with a one-dimensional chain structure

Abstract The polymeric silver(I)–thiolate complex [Ag6(μ3-SC4N2H3)4(μ2-SC4N2H3)2]n has been prepared from the assembly reaction of AgSCN and sodium pyrimidine-2-thiolate in DMF. X-ray diffraction analyses show that the complex exhibits a one-dimensional chain structure with the metal atom core arranged in distorted tetrahedra sharing apexes. The pyrimidime-2-thiolate ligands in the chain act as both bridging and chelating ligands linking either two- or three-silver(I) centers. The coordination environment of each Ag(I) in the complex is either a distorted tetrahedron of S3N or a triangle of S2N.

Designed synthesis for some transition metal clusters involving bridging-sulfido ligand

Designed synthesis for some transition metal clusters involving bridging-sulfido ligands is reviewed. The basic concept with the use of reactive fragments as building blocks is described. It is shown that the sulfido ligands with lone-pair electrons and the unsaturated coordination sites play important roles in this rational synthesis. The relationship between the metallic coordination types of the sulfido ligands and their assembling activity in the compounds is summarized. Examples of the six kinds of “unit construction” with reactive fragments as building blocks are shown, indicating clearly that the “unit construction” is a reasonable way in the synthesis of transition metal clusters involving bridging sulfido ligands. Finally, the potential application of the “unit construction” schemes in the synthesis of transition metal clusters involving other bridging ligands is presented.

Transition metal 1,2-bidentate thiolates as building blocks and their construction into cluster complexes

Simple fragments of transition metal 1,2-bidentate thiolates, the so-called building blocks of the general compositions ML3, ML2, ML, M(O)L2, ML2L′, MLL′, etc. have been proposed to constitute the di-, tri- and tetranuclear complexes concerned in this review. Structureal regularities and characteristics have been discussed and summarized according to the thiolato ligands edt and pdt, bdt and tdt, mp, and mpo, and mpp, respectively.

A tetranuclear silver complex with dppm and i-mnt ligands. Synthesis and structural characterization of [Ag4(μ-dppm)4(μ4 i-mnt)2] · 0.5 DMF (i-mnt 2,2-dicyano-1,1-ethylenedithiopate; dppm bis(diphenylphosphino)methane)

Abstract The reaction of [Ag(dppm) (NO3)]2 (1) with potassim i-mnt  2,2-dicyano-1,1-ethylenediothiolate; dppm  bis (diphenylphosphino)methane) in DMF at room temperature gave rise to the complex [Ag4(μ-dppm)4(μ4-S2C=C(CN)2)2] (2). The crystal structure of 2 has been determined by single crystal X-ray diffraction analysis. 2 is a tetranuclear complex with a silver-silver separation of 3.376(2) A and the four silver atoms form a distorted square plane bridged by four dppm and two i-mnt ligands. Each silver atom is coordinated by two phosphorus and two sulfur atoms in a distorted tetrahedral environment. The IR, 1H and 31P NMR spectroscopic properties of 2 have also been investigated.

Cobalt complexes with pnicogen (phosphine or pyridine) and thiolato ligands. Syntheses, X-ray crystal structures and spectroscopic characterization

Abstract Mixed pnicogen and thiolato mononuclear cobalt complexes, Co(SR)2(PBun3)2 [R = Ph (1); R = Stolyl-p (2)] and Co(mpo)2L [L = PBun3 (3); L = Py (4)], have been synthesized and studied spectroscopically. The complexes 1 and 2 are tetrahedral, as determined by magnetic susceptibility studies. The structures of 3 and 4 were determined by X-ray diffraction. The cobalt(II) ions in both 3 and 4 are in a square-pyramidal environment with the two trans-oriented mpo ligands in the basal plane and the pnicogen group in the axial position.

X-ray crystal structures of Mo3S4(DTP)3(salicylate)(CH3CN) and [Mo3S4(DTP)3(phthalate)(Py)]2 · EtOH · CH2Cl2: intramolecular H-bonds and S–S interactions in trinuclear molybdenum cluster compounds

Abstract Two new molybdenum cluster compounds, Mo3S4(DTP)3(salicylate)(CH3CN) and [Mo3S4(DTP)3 (phthalate)(Py)]2 · EtOH · CH2Cl2, have been rationally synthesized by the ligand substitutional reaction of Mo3S4(DTP)4(H2O) with salicylic acid and phthalic acid, respectively. Their crystal structures have been determined. A molecular-design method for Mo3S4 cluster compounds was developed. Two incomplete cuboidal molybdenum cluster units can be linked by intramolecular H-bonds.

Electronic structures and dpπ bonding of some M3X4+4 cluster compounds

Abstract Using a quantum chemical ab initio method with relativistic effective core potentials, electronic structures of the group VI cluster cores M 3 X 4+ 4 (M = Mo, W; X = O, S, Se, Te) and the oxoselenido cluster cores M 3 O n Se 4+ 4− n (M = Mo, W; n = 0–4) in trinuclear incomplete cubane-type compounds have been calculated at the level of self-consistent field with inclusion of d -orbitals in the basis sets of oxygen, sulphur, selenium and tellurium atoms. By virtue of the calculated canonical molecular orbitals (CMO) and localized molecular orbitals (LMO), the nature of d  p π bonding and its effect on the stabilities and reactivities in substitution and addition reactions of the clusters are discussed. The clusters under consideration have been shown theoretically to exhibit what we have previously chosen to call “quasi-aromaticity”, i.e. having benzene-like behaviour. The influence of the d -orbitals of group VI atoms is considered.