Preparation and electrical conductivity of organoheterobimetallic-maleonitriledithiolates

The new complexes [PhHg]₂[M(mnt)₂] [M = Ni^II, Cu^II, Zn^II or Pd^II; mnt^2– = 1,2-dicyano-1,2-ethylenedithiolate (maleonitriledithiolate)] have been characterized spectroscopically and magnetically and their solid phase conductivity measured. All compounds exhibit solid phase _rt in the 1.29 × 10^–12–5.68 × 10^–10 S cm^–1 range and semiconduct in the 313–383 K range.     

Enhanced light harvesting efficiencies of bis(ferrocenylmethyl)-based sulfur rich sensitizers used in dye sensitized TiO2 solar cells

In this work, the photosensitizing properties of ferrocene (Fc)-based compounds FcCH(2)CS(3)CH(2)Fc (1) and FcCH(2)SSCH(2)Fc (2) were investigated and significant enhancement in the light harvesting efficiency was observed compared to those achieved with previously reported compounds from our lab. The compounds were fully characterized by spectroscopy and X-ray crystallography, and their electrochemical properties studied. DSSCs based on these dyes display efficiencies comparable to those of a standard cell based on N719 under similar experimental conditions. These studies demonstrate that ferrocenyl-based sulfur rich compounds with proper orientation of the Fc groups assisted via suitable linkers, together with desired redox properties and visible region electronic absorption features could constitute a new class of photosensitizers targeting light driven reactions.     

Preparation and characterization of heterobimetallic tetraxanthates and their complexes with Lewis bases

Some new heterobimetallic tetraxanthates of the type M[Ag(Etxant)₂]₂ [M = Co(II) or Ni(II), Etxant = ethylxanthate] and their complexes of general formula M[Ag(Etxant)₂]₂.xL [x = 2 when L= dimethylsulphoxide (DMSO), triphenylphosphine (Pph₃), pyridine(py) or 2-aminopyridine (2-ampy); x = 3 when L = 2,2′-bipyridine (bipy)] have been prepared and characterized by elemental analysis, molar conductance, magnetic susceptibility, infrared and electronic spectral studies. Magnetic and electronic spectral studies indicate square planar geometry around Ni(II) and Co(II) in heterobimetallic tetraxanthates and Ni[Ag(Etxant)₂]₂.2PPh₃ and octahedral geometry around the above metal ions in the remaining complexes.     

Preparation,characterization and electrical conductivity of new heterobimetallic chalcogenates and their 1,10-phenanthroline adducts

New mixed metal chalcogenate coordination polymers, MPb(SCN)₂(SeCN)₂ [M = Co^II, Ni^II or Hg^II], Ag₂-Pb(SCN)₂(SeCN)₂, and the complex heterobimetallic salts, [M(phen)₃][Pb(SCN)₂(SeCN)₂][M = Co^II or Ni^II; phen = 1,10-phenanthroline] that have been prepared and characterized by elemental analyses, i.r. and u.v.–vis. spectra, and by powder XRD patterns. Their solid state electrical conductivities have been investigated, show _rt in the 10^–10–10^–6 S cm^–1 range, and semiconduct at 313–383 K with band gaps in the 0.28–0.91 eV range. [Co(phen)₃][Pb(SCN)₂(SeCN)₂], exhibits a remarkable increase, i.e. 10⁴ order of magnitude, in conductivity at higher temperature, which reflects a disordered metallic system where charge carriers have difficulty in crossing the non-conducting barrier at low temperature.     

Composition-dependent phase separation effects of organic solar cells using P3HT:PCBM as active layer and chromium oxide as hole transporting layer

Phase separation of the poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) active layer (ATL) was investigated by varying their relative ratio in the organic solar cells (OSCs). With the help of the UV/visible spectrophotometer, optical microscopy and scanning electron microscope, we found that the cluster of PCBM at the interface or surface was affected by Al cathode, the composition of the blends and thermal annealing. The disc-like shape crystals of PCBM substituted for the needle-like ones at higher PCBM compositions at the ATL/Al interface, which led to stronger contacts and bigger contact area. It could make short circuit current density increase, but may affect the blend morphology and result in parallel resistance and open circuit voltage decreased with the PCBM ratio increasing from 40 to 60%. The microstructure of the P3HT:PCBM ATL, determined by the composition dependent phase separation, supported the optimized performance of the OSCs with the composition of 40-50% PCBM.     

TMB法测定水中游离余氯的改进

介绍了一种改进试剂后测定水中游离余氯的TMB比色法。结果表明，其检测过程快速、便捷；精密度和准确度均能达到分析要求。     

New heterometallic coordination polymers derived form chalcogenocyanates: synthesis,characterization and electrical properties

A series of conducting mixed-metallic coordination polymers: Cu₂Pb(SCN)₄, CuPb(SeCN)₄, Cu^II _0.50Cu^IPb (SCN·SeCN)₂, CuAg(SCN)₂, CuAg(SeCN)₂ and CuAg(SCN·SeCN) have been synthesized by the reaction of Cu and Pb^II or Ag^Initrates with KSCN or KSeCN, or both KSCN and KSeCN in H₂O. Of significance are the aerobic reactions which yield heterometallic complexes viaoxidation of SCN^– and SeCN^– into (SCN)₂ and (SeCN)₂ followed by quantitative reduction of Cu^II into Cu^I; in the case of CuPb(SeCN)₄ reduction of Cu^II into Cu^I is not observed, while in Cu^{II 0.50}Cu^IPb(SCN·SeCN)₂, Cu^II is partially reduced to Cu^I. These compounds have been characterized by elemental (C, N, S and Se) analyses, magnetic moment measurements, relevant spectroscopies (i.r., far i.r., Raman, u.v.–vis. and e.p.r.), powder X-ray diffraction pattern and conductivity technique. The v(CN) vibrations in 2162–2087cm^–1 and far i.r. bands (500–100cm^–1) corroborated by Raman bands are conclusive of the bridging (N, S/Se) mode and metal-NCS and metal-SCN/SeCN^– bonding respectively in the complexes. Room temperature magnetic moment, electronic absorption spectra and e.p.r. active/silent nature confirm the oxidation state of copper in these solids. Room temperature compressed pellet conductivities _rt, 10^–9to 10^–7Scm^–1 with activation energies, E _a=0.19–0.25eV and increase in the conductivity with increase in temperature in the 305–423K, range and decrease in conductivity with decrease in temperature in the 295–200K range, show their semiconductor properties.     

Facile in situ copper(II) mediated C-S bond activation transforming dithiocarbimate to carbamate and thiocarbamate generating Cu(II) and Cu(I) complexes

Facile in situ Cu(II) mediated transformation of p-tolylsulfonyldithiocarbimate in conjunction with polypyridyl or phosphine ligands into corresponding carbamate and thiocarbamate led to the formation of new copper complexes with varying nuclearities and geometries, via C-S bond activation of the ligand within identical reaction systems.     

Preparation,spectroscopic investigation and antibacterial activity of some organomercury(II) and organotin(IV) dithio complexes

Phenylmercuric acetate, triphenyltin chloride and dibutyltin chloride react with alkali‐metal or ammonium salts of some 1,1‐ and 1,2‐dithio ligands in appropriate molar ratios to yield a series of organometallic dithio complexes of the type [PhHgX] (X = butylxanthate (Buxant⁻), cyclohexylxanthate (Cyxant⁻), benzylxanthate (Bzxant⁻) or pyrrolidin‐1‐yldithiocarbamate (Pdtc⁻); [(PhHg)₂X] (X = isomaleonitriledithiolate (i‐MNT²⁻) or 1‐ethoxycarbonyl‐1‐cyanoethylene‐2,2‐dithiolate (ecda²⁻); Ph₃SnX (X = Buxant⁻ or Pdtc⁻); [(Ph₃Sn)₂(i‐MNT)] and [Bu₂SnMNT] (MNT²⁻ = maleonitriledithiolate). These complexes have been characterized by elemental analysis, molar conductance measurements, IR, FT‐Raman, ¹H and ¹³C NMR and fast atom bombardment (FAB) mass spectra. Cyclic dimeric structures for phenylmercuryxanthates and monomeric structures for the remaining complexes are suggested. Antibacterial activities of the complexes and parent ligands have been screened against some well‐known pathogenic bacteria. Organomercury dithiolates have been found to be more potential antibacterial than organotin complexes. Copyright © 2000 John Wiley & Sons, Ltd.     

Synthesis,Structure and Light‐Harvesting Properties of Some New Transition‐Metal Dithiocarbamates Involving Ferrocene

Nine new transition‐metal dithiocarbamates involving ferrocene (Fc), namely, [M(FcCH₂Bzdtc)₂] (M=Ni^II ( 1 ), Cu^II ( 2 ), Cd^II ( 3 ), Hg^II ( 4 ), Pd^II ( 5 ), Pt^II ( 6 ) and Pb^II ( 7 ); Bzdtc=N‐benzyl dithiocarbamate) and [M(FcCH₂Bzdtc)₃] (M=Co^II ( 8 ) and UO₂^VI ( 9 )), have been synthesised and characterised by micro analyses, IR spectroscopy, ¹H and ¹³C NMR spectroscopy, and in three cases by single‐crystal X‐ray analysis. The peak broadening in the ¹H spectrum of the copper complex indicates the paramagnetic behaviour of this compound. A square‐planar geometry around the nickel and copper complexes and distorted linear geometry around the mercury complex have been found. The latter geometry is attributed to the bulkiness of the methylferrocenyl and benzyl groups. The observed single quasi‐reversible cyclic voltammograms for complexes 2 , 8 and 9 indicate the stabilisation of a metal centre other than Fe in their characteristic oxidation state. These complexes have been used as a photosensitiser in dye‐sensitised solar cells.