-Quan Xin

MO(W,V)-CU(AG)-S(SE) CLUSTER COMPOUNDS

Abstract This review summarizes the preparation, skeletal structure, reactions, spectroscopic properties and non-linear optical properties of Mo(W,V)Cu(Ag)S(Se) cluster compounds; 190 such compounds belong to 23 structural types; 25 reactions are classified into ligand substitution, addition and decomposition reactions. Recently, some Mo(W)Cu(Ag)S clusters were found to exhibit strong non-linear optical properties; the optical limiting threshold measured for [(PPh 3 ) 4 Ag 4 Mo 2 S 8 ] is one order of magnitude lower than that of C 60 .

A linear piperazine-pyridine ligand and its Hg coordination polymer

Abstract Reaction of piperazine hexahydrate with 4-chloromethylpyridine hydrochloride affords a new piperazine–pyridine ligand: N,N′-bis(4-pyridylmethyl)piperazine (bpmp). X-ray structure analysis confirms an overall linear structure, in which the lone electron pairs of piperazine-N are in trans-position. Its zigzag polymer with Hg2+ was readily obtained in THF. Bpmp is held in the chair conformation in the polymer, and Hg2+ coordinates to two N atoms from different bpmp ligands and two I atoms.

Syntheses and Structures of Transition Metal-hedp Compounds and the Template Influences (hedp = 1-Hydroxyethylidenediphosphonate)

Abstract The chemistry of metal phosphonates has been of increasing interest during the past two decades, owing to their practical applications as ion exchangers, catalysts and sensors. Great efforts have been devoted to the metal diphosphonates, by modifying the organic tether (R) of R(PO3H2)2, to explore new materials with large pores and interesting functions. The template effect on directing the formation of different metal diphosphonate structures, however, has not been well documented. We present here the syntheses and structures of eleven M-hedp compounds, where M = Cu, Fe, Ni; hedp = 1-hydroxyethylidenediphosphonate. The influences of templates on the final products are discussed.

Heteroselenometallic cluster compounds with tetraselenometalates

Abstract The coordination cluster compounds of tetraselenomolybdate and tetraselenotungstate anions with metal ions are reviewed. New heteroselenometallic cluster compounds are primarily of interest regarding their structures and reactivities, and their potential as non-linear optical (NLO) materials. This article focuses from a synthetic and structural point of view on coordination cluster compounds with tetraseleno-molybdate and -tungstate anions as polydentate ligands. A comprehensive survey is presented of the heteroselenometallic clusters known to date according to the number of center [MSe 4 ] 2− (M=Mo, W) anions. Representative spectroscopic and NLO properties of these clusters are also discussed.

Solid-state synthesis of cluster compound [MoCu3OS3(PPh3)3(CH3COO)] with its structure, reactivity and optical non-linearities

Abstract A novel acetate-containing cluster compound [MoCu 3 OS 3 (PPh 3 ) 3 (CH 3 COO − )] was synthesized via a low-heating solid-state synthetic method. For the first time, the O-containing ligand was introduced into the Mo(W)Cu(Ag)S clusters with the O atoms acting as the coordinating atoms. The structure of this compound has been characterized by X-ray diffraction: space group P -1, Z = 4, R = 0.052, R w = 0.058. A series of reactions manifest the possible role of the binuclear structure of Cu(CH 3 COO) 2 ·H 2 O in the synthetic process as well as the relative weak affinity of the acetate group for Cu(I) compared with that of the halogen atoms. Z-scan measurements show that this compound exhibits interesting non-linear optical (NLO) effects.

Two interesting heterobimetallic compounds [MOS3Cu3(4-pic)6]·Br (M=Mo, W) with cationic cluster: synthesis, structural characterization, non-linear response and large optical limiting properties

Abstract Two heterobimetallic cluster compounds [MOS 3 Cu 3 (4-pic) 6 ]·Br (M=Mo, W) with cationic cluster skeleton and halide anion Br − synthesized by the reaction of (NH 4 ) 2 MOS 3 , CuBr and 4-picoline (4-pic) are presented. Their structures have been crystallographically determined and such nest-shaped cationic clusters, obtained for the first time, are interesting in comparison with the analogical nest-shaped clusters with a neutral skeleton or anionic skeleton. The non-linear optical (NLO) properties of these two clusters are investigated with an 8 ns pulsed laser at 532 nm. These two clusters exhibit large optical limiting abilities with limiting thresholds F th =0.18 J cm −2 ( 1 ) and F th =0.15 J cm −2 ( 2 ), respectively. Both compounds show strong third-order NLO absorption effects ( α 2 -value of 1.6×10 −10 m W −1 ( 1 ), 2.8×10 −10 m W −1 ( 2 )) and self-focusing performance ( n 2 -value of 4.56×10 −11 esu ( 1 ), 4.62×10 −11 esu ( 2 )) in 3.86×10 −4 mol dm −3 ( 1 ) and 8.89×10 −4 mol dm −3 ( 2 ) DMF solution separately. The corresponding effective NLO susceptibilities χ (3) are 5.4×10 −12 esu ( 1 ) and 5.5×10 −12 esu ( 2 ) while the corresponding hyperpolarizabilities ( γ ( 1 ) =2.51×10 −31 esu and γ ( 2 ) =1.03×10 −31 esu) are also reported.

Sonochemical synthesis of size-controlled mercury selenide nanoparticles

A novel sonochemical method for preparation of mercury selenide has been developed based on the reaction of mercury acetate and sodium selenosulfate in an aqueous system at room temperature. Different complexing agents were used to control the particle size. X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used to determine the phase, purity, size and morphology of the products. The results showed that the HgSe nanoparticles with different sizes could be obtained in the presence of complexing agents.

Synthesis, crystal structure and nonlinear optical properties of two new cluster compounds: [WCu3S4(PPh3)3{S2P(OCH2Ph)2}] and [WAg3OS3(Ph3P)3{S2P(OPri)2}]

Abstract Two new O , O ′-dialkyl dithiophosphate-containing sulfido clusters, [WCu 3 S 4 (PPh 3 ) 3 {S 2 P(OCH 2 Ph) 2 }] 1 and [WAg 3 OS 3 (Ph 3 P) 3 {S 2 P(OPr i ) 2 }] 2 , were synthesized through reactions of [NH 4 ] 2 [WS 4 ] with [CuS 2 P(OCH 2 Ph) 2 ] and [NH 4 ] 2 [WOS 3 ] with [AgS 2 P(OPr i ) 2 ], respectively. Their crystal structures and nonlinear optical properties are reported. The X-ray crystallographic structure of 1 is an incomplete cubane-like structure, the dithiophosphate ligand adopts a triply bridging role, employing two sulfur atoms to coordinate to the three Cu atoms: one sulfur atom binds to one Cu atom, another sulfur atom to two other Cu atoms. The structure of 2 contains a half-open cubane-like cluster core, the dithiophosphate ligand acts as a bidentate ligand and the two S atoms of the di-isopropyl dithiophosphato ligand coordinate to two Ag atoms, respectively. Using a Z -scan technique with 532 nm laser radiation, both the real and imaginary parts of third-order nonlinear susceptibility of clusters 1 and 2 were determined.

Strong optical limiting (OL) capability of the two-dimensional network cluster polymer [MoS4Cu6I4(py)4]n

The two-dimensional network compound [MoS4Cu6I4(py)4]n is the first example of a cluster polymer showing very large optical limiting effects; its nonlinear absorptive index α2 and nonlinear refractive value n2 are 1.5 × 10–9 m W–1 and –2.5 × 10–17 m2 W–1, respectively, in 6.5 × 10–5 mol dm–3 DMSO solution; the optical limiting threshold was determined to be 0.6 J cm–2, which is about three times better than that of C60.

Synthesis, structural characterization of a novel 4,4 '-bipyridyl based HgI2 adduct

A novel mercury iodide adduct, [HgI2(4,4′‐bipy)]n, was synthesized by the reaction of HgI2with 4,4′‐bipyridine in THF. The structure characterization was performed by means of IR, elemental analyses and single crystal X‐ray analysis. The structure of [HgI2(4,4′‐bipy)]nconsists of distorted tetrahedral Hg(II) centers bridged by 4,4′‐bipy ligands to form one‐dimensional zigzag chains without iodide bridging.