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Twelve new zinc(II) and cadmium(II) complexes with symmetric ligands, [MCl2((R2N)3PO)2] (M = Zn, R2N = pyrrolidinyl (1), piperidinyl (2); M = Cd, R2N = pyrrolidinyl (3), piperidinyl (4)), and diffe...

Two binuclear complexes, fac-[Cd2(AEPC)2(μ-Cl)2Cl2] ( 1 ) and [Hg2(AEPC)2(μ-Cl)2Cl2] ( 2 ), of 2-(2-(pyridin-2-yl)oxazolidin-3-yl)ethanol (AEPC) were prepared and identified by elemental analysis, FT-IR, 1H NMR spectroscopies, and single-crystal X-ray diffraction. All coordination modes of 2-(pyridin-2-yl)oxazolidine derivatives were studied by analysis of the Cambridge Structural Database (CSD) for determination of coordination behaviors of the AEPC ligand with metals. In the crystal structure of 1 , the cadmium ion has a distorted octahedral geometry and CdN2OCl3 environment in which each ligand acts as an NN′O-donor. In the crystal structure of 2 , the AEPC acts as NN′-donor toward the mercury ion to form a square-pyramidal geometry with three chloride ions. Each complex contains four chiral centers with a center of inversion and Ci symmetry. In the crystal networks of the complexes, the alcohol groups of the ligands participate in hydrogen bonding and form R44(28) and R66(44) hydrogen bond motifs (observed for 1 ). In addition to the hydrogen bonds, the crystal network is stabilized by π—π stacking interactions between pyridine rings of the AEPC ligands of adjacent complexes. The thermodynamic stability of the isolated complexes and their charge distribution patterns were studied by DFT and NBO analysis. Postprint

The authors are grateful to the Tunisian Ministry of High Education and Scientific Research for financial support (LR99ES14) of this research. Four new zinc(II) complexes of the type [ZnCl2(n-Bu3PE)2] (E = O ( 1 ), S ( 2 ), Se ( 3 ) or Te ( 4 )) have been synthesized from zinc(II) chloride and the ligands n-Bu3PE giving yields of 56-88%. The adducts were characterized by multinuclear (31P, 13C and 77Se) NMR, conductivity, IR spectroscopy and by X-ray analyses. The zinc complexes 1 – 4 are comprised of two ligands coordinated to the metal centre in a distorted tetrahedral arrangement. The P=E bond lengths of 1.497(7) (E = O), 2.000(4) (E = S) and 2.178(2) Å (E = Se) in these complexes are slightly elongated compared to those in the free ligand. In addition, a DFT/B3LYP theoretical study on the geometry optimization of the title ligands and their zinc complexes has been carried out in order to support and complement the experimental data and to further investigate the nature of the chalcogenide-metal interaction. The results show good agreement between the experimental and theoretical data. Postprint

EZ-C acknowledges the University of St Andrews for financial support. The authors are grateful to the EPSRC for financial support from grant EP/M02105X/1. JMR would like to thank NSERC Canada, the Canada Research Chair Program and CFI/ORF for financial support. KP acknowledges financial support through the Ontario Trillium Scholarship program. Reaction of Tetrakis(2-phenylpyridinato-C2,N')(μ-dichloro)di-iridium with 3-(pyridin-2-yl)-4H-benzo[e][1,2,4]thiadiazine ( L1 ) under neutral and basic media afforded the charged and neutral Ir-complexes, 1 and 2 , respectively, in good yields (63 – 79%). Single crystal XRD analysis confirms that the ancillary ligands in both 1 and 2 binds to the iridium via coordination of N2 of the benzo[e][1,2,4]thiadiazine. Upon isolation of the neutral complex, the sulfur atom rapidly oxidizes to form 2 . The UV-vis absorption spectra of the complexes exhibit both ligand-centered and mixed metal-to-ligand and ligand-to-ligand charged transfer (CT) transitions that are typical of many heteroleptic iridium complexes. Complexes 1 and 2 were found to be emissive at room temperature in the green and yellow region of the electromagnetic spectrum, respectively, albeit with poor photoluminescence quantum yield (ΦPL = 1.1 – 2.5%). Publisher PDF

A series of new selenium-containing heteroatom compounds were synthesized in good yields by the reactions of Woollins’ reagent with various organic substrates such as cyclohexanamine, N-benzoylbenzamide, benzoic anhydride, 4-fluoro-N-(2-oxo-2-phenylethyl)benzamide, N-benzoylbenzamide, benzoic anhydride, 3-(bromomethyl)benzonitrile, 1,2-diphenylethane-1,2-diol and sodium alcoholate. Three representative X-ray structures are described. Postprint Postprint

A new salicylaldehyde-based ‘ONS’ tridentate salicylaldehyde-N(4)-diethylthiosemicarbazone (H2SANEt2) has been synthesized and characterized by elemental analyses, mass, IR, and 1H NMR spectral parameters. The coordination mode of the synthesized ligand is reported by solid state isolation and physico-chemical identification of Ni(II) and Cu(II) complexes, [Ni(SANEt2)]2 (1) and [Cu(SANEt2)]2 (2). Both complexes are neutral and oxygen-bridged dinuclear species. The ligand is bideprotonated ‘ONS’ tridentate in both complexes. IR spectral data indicate that coordination of each metal of the two complexes occurs through phenolic oxygen, azomethine nitrogen, and thiolato sulfur. X-ray crystallographic data of 1 and 2 (both monoclinic, P21/c) show a MONSO (where M=Ni and Cu) square-planar coordination around each metal. Magnetic studies of 2 show that the two Cu(II) centers are strongly antiferromagnetically coupled via the bridging phenoxo O. All the synthesized compounds were tested for their in vitro antimicrobial activities against pathogenic bacteria. The inhibition power of the complexes was greater than the parent ligand.

Two new (NS)2 Schiff bases, (4-NO2Ph)2dapte (N,N′-di-(4-nitrobenzaldimine)-1,2-di(o-aminophenylthio)ethane) (1) and (thio)2daptx (N,N′-di-(thiophenedimine)-1,4-di(o-aminophenylthio)xylene) (2), and their 1-D copper(I) coordination polymers [Cu2(μ-Br)2(μ-(4-NO2Ph)2dapte)] n (3), [Cu2(μ-I)2(μ-(4-NO2Ph)2dapte)] n (4), and [Cu2(μ-I)2(μ-(thio)2daptx)] n (5) have been synthesized and characterized by elemental analyses and IR, UV-Vis, and 1H NMR spectroscopy. The structures of 4 and 5 have been determined by X-ray crystallography and were shown to consist of Cu2(μ-I)2 secondary building units (SBUs) bridged by (4-NO2Ph)2dapte or (thio)2daptx ligands. The CuNSI2 coordination sphere is a distorted tetrahedral in both cases. Both (4-NO2Ph)2dapte and (thio)2daptx are N2S2-bis-bidentate chelating ligands with the two imine nitrogens and two thioether sulfurs in a trans configuration generating dinuclear [Cu2(μ-(4-NO2Ph)2dapte)] and [Cu2(μ-(thio)2daptx)]. These units are connected by two bridging iodides to form 1-D ...

Several new iron(II) triflate complexes of 6-py-substituted derivatives of tris(2-pyridylmethyl)amine (TPA); [Fe(3–6)(CH3CN) x ](CF3SO3)2 (3 = tris-(6-methoxymethyl-2-pyridylmethyl)amine, x = 0; 4 = tris-(6-octoxymethyl-2-pyridylmethyl)amine, x = 0; 5 = 6-(N′-hexylureido-2-pyridylmethyl)-bis(2-pyridylmethyl)amine, x = 1; and 6 = bis-(6-(N′-hexylureido)-2-pyridylmethyl)-2-pyridylmethylamine) have been synthesized to probe the introduction of a hydrophobic peralkyl chain (4–6) and hydrogen-bonding (from urea N–H) (4 and 5) on the selective catalysis of alkane oxygenation by H2O2 in CH3CN. For [Fe(6)](CF3SO3)2, hexadentate coordination of iron involving the two urea carbonyls was confirmed by X-ray structural analysis. Despite this, [Fe(6)](CF3SO3)2 exhibited the highest A/K ratio (3.3), yet seen for catalysis of H2O2 oxygenation of cyclohexane by an iron(II) complex of a bis(6-py)- or tris(6-py)-substituted TPA derivative. This has been tentatively attributed to a degree of O–O cleavage assistance within hi...

The degradation of Nitrilotriacetic Acid (NTA), which results from the oxidation of hydroxyl radicals formed in the process, is a major deficiency in the present Fe-NTA system for the oxidation of hydrogen sulfide to sulfur by air. The degradation of NTA can be slowed down considerably by the addition of a hydroxyl radical scavenger. In this study, a series of inorganic and organic materials was tested as scavengers/inhibitors of hydroxyl radicals in attempts to improve the Fe-NTA system. The results showed that N-methylpyrrolidinone and ethylene glycol could be used as potentially powerful scavengers of hydroxyl radicals to improve the Fe-NTA system.

The psuedohalogens (ECN)2 (E = S, Se) have been prepared by reaction of AgNCS with bromine and AgNCSe with iodine respectively. (SCN)2 spontaneously polymerises to give polythiocyanogen a polymer of unknown structure with empirical formula (SCN)x. A series of late transition metal complexes bearing the ambidentate psuedohalide ligands (ECN) (E = S, Se) have been synthesised. In addition we have prepared a series of late transition metal complexes of the cyanodithioimidocarbonate ion [C2N2S2]2− and the first transition metal complexes of the cyanodiselenocarbonate ion [C2N2Se2]2−.

The addition of dichloromethane solutions of carbon diselenide to liquid ammonia containing suspensions of platinum bis-phosphine dichlorides [PtCl2(PRX)n] (n = 2, (PRX) = PMe3, PMe2Ph, PMePh2, and PPh3, n = 1, (PRX) = dppm, dppe, dppp, dppf) gives, after evaporation of the ammonia and extraction of the reaction residues with dichloromethane, the appropriate platinum bis-phosphine triselenocarbonate complexes in reasonable yields (40–60%).

NMR properties of 1,8-diphosphanaphthalenes with prerequisites for strong through-space interaction were studied. The exceptional magnitude of 4J(PP) 246 Hz was found in Nap[P(NMe2)2][P(OMe)(NMe2)] (Nap = naphthalene-1,8-diyl). The PIII, PV mixed valence systems Nap[P(E)(OMe)2][P(OMe)2] (E = O, S, Se) show much lower magnitudes of through-space interaction than expected.

Unsymmetrically substituted α‐hydroxy ketones possessing isoprenoid units within the molecule were synthesised from commercially available terpene aldehydes. The synthesis was applicable to α,β‐unsaturated aldehydes and afforded the respective α‐hydroxy‐methyl ketones in overall good yield. Tautomerisation of these products did not occur under the conditions of reaction but was observed upon heating. Diastereoisomeric α‐hydroxy ketones have been resolved, and X‐ray analysis on one of these analogues allowed for the elucidation of the stereochemistry after conversion into its camphanate ester.

The compounds (PhP)3Se2 1 and [{PhPSe(μ-Se)}2] II, prepared by selenium oxidation of the homocycle (PhP)5, react with simple unsaturated organic substrates to give highly unusual P-Se-C-N containing heterocycles.

The dimeric compound [( n-Bu2Sn)S2N2]2 is readily prepared by addition of n-Bu2SnCl2 to a liquid ammonia/[S4N3][Cl] reaction mixture. Reaction of [ n-Bu2SnS2N2]2 with mono and dimeric organometallic M(III) (M = Rh, Ir) complexes bearing Cp* ligands (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl) and M(II) (M = Ru, Os) phosphine complexes containing a cis arrangement of chlorides gives compounds with MS2N2 metallacycles.

By the hydrothermal reaction of lead (II) acetate with 2-benzonylbenzoic acid, colourless crystals of a hexanuclear lead carboxylate with bridging oxide ligands was obtained. The structure of the molecule could be described as being like a tennis ball of lead atoms at the centre of a soccer ball of carboxylate ligands. For clarity the carboxylate and oxide ligands have been omitted.

The magnetic and electrical characterization of the radical salts formed by the organic donor bis(ethylenedithio)tetrathiafulvalene (abbreviated to ET) and the large inorganic clusters [B10I10]2− and [P2W18O62]6− are presented.

Reaction of diphenylphosphino-2-aminopyridine with a variety of late transition metal species eg Pt (II), Pd (II), Ru (II) and Rh (III) in most cases leads to five-membered metallocycles containing M-P-N(H)-C-N rings. Treatment of these species with base results in deprotonation of the amino group, formation of a neutral species and election delocalisation over the P-N bond.

Reaction of [Ph2P(E)NP(E)Ph2]− (E = S or Se) with a series of late transition-metal dimers, in thf or MeOH, leads to facile bridge cleavage and formation of new mononuclear compounds.

The compounds [Mo(N3S2){Ph2(O)PNP(S)Ph2}2] 1 [Mo(N3S2){iPr2(O)PNP(S)iPr2}2] 2 have been synthesised by treating [MoCl3(N3S2)] with KN(PPh2S)2 or KN(PiPr2S)2. X–Ray structures of 1 and 2 have been solved. On complexation, the MoN3S2 ring remained planar, but the Mo(OPNPS)2 rings are puckered.

The anion [N(SePPh2)(2)](-) forms stable complexes with cations M(II, III); [M(II) = Sn, Se, Cd, Hg; M(III) = In, Sb, Bi], they exhibit a large diversity of structural arrangements around the metal centre. Tin(II) complex crystallizes dimorphically, as square planar and distorted tetragonal pyramidal, Pb(II) is also distorted tetragonal pyramidal, Cd(II) and Hg(II) are tetrahedral, but the Se(II) is square planar. The coordination geometry in the M(III) complexes can be described as a distorted octahedron. The structural situation around the Sb(III) and Bi(III) suggests a stereochemically non-active electron lone pair.

Several new palladium(II) complexes of [Ph2P(O)NP(E)Ph2]− (E = S or Se) have been prepared in which a variety of ligating modes (O,E-chelating, E-bridging and E-monodentate) are observed.

Adducts of diselenium dinitride, a species as yet unknown in the free state, may be prepared with either palladium or aluminium as the metal centre. Thus salts of [Pd2X6]2- (X = CI or Br) react with Se4N4 at 100°C in CH2Cl2 to give [Pd2X6(Se2N2)]2- while A1X3 reacts with the same reagent, at ambient temperatures in CH2X2, to give [(AlX3)2(Se2N2)]. When X = Cl in the latter case the product cannot be obtamed in pure crystaUine form; here we present IR data which confirms the presence of the neutral Se2N2 unit.

Diferrocenyl dithiadiphosphetane disulfide (Fc2P2S4) had been found act as a source of a reactive species, believed to be FcPS2, which reacts with dialkyl cyanamides, imines, aldehydes and strained alkenes to form a variety of phosphorus compounds. These reactions include a convenient route to thiaphosphetanes.

We report on the formation of a Cu3S3 heterocycle from the reaction of copper(II) bromide and the ligand [NH( i Pr2PS)2] bis(diisopropyldithiophosphino)amine. The single crystal X-ray structure and other spectroscopic details are presented. The molecule exists as a six membered ring which displays a single peak in its solution 31P NMR though different phosphorus environments are evident in the solid state.

The preparation of iPr2P(S)NHP(S)iPr2 and its reaction to form simple chelate complexes M(iPr2P(S)NP(S)iPr2)2 (M = Pd, Pt) is described. The neutral starting material forms H-bonded chains in the solid state whilst there are dramatic differences in ring geometry on changing M from Pd to Pt.

A series of rhodium(III) half sandwich complexes of the type [Cp*Rh(PMe3)(S—R—S)]; S—R—S = naphthalene-1,8-dithiolate, acenaphthene-5,6-dithiolate, [1,1′-biphenyl]-2,2′-dithiolate and [2,2′-binaphthalene]-1,1′-dithiolate are reported. In the case of [2,2′-binaphthalene]-1,1′-dithiolate this represents an infrequent example of a metal complex containing this ligand. All the complexes have been fully characterised using multinuclear NMR spectroscopy and single crystal X-ray diffraction. The single crystal X-ray structure of the starting material [Cp*Rh(PMe3)Br2] ( 1 ) is also reported for the first time. Publisher PDF

The reaction of Pt(Se2N2)(dppe) (1) with stoichiometric quantities of halogen (Cl2, Br2 or I2) in CH2Cl2 yields PtX2(dppe) and Se4N4. In the case of iodine the rate of reaction was much slower than for the other halogens and 31P n.m.r. evidence suggests that the reaction proceeds via the protonated complex [Pt(Se2N2H)(dppe)]I. The crystal structure of 3[PtI2(dppe)]·I2·2[CH2C2] is reported

The crystal and molecular structures of two closely related antiviral purine derivatives are reported. In 9-[4-hydroxy-3-(hydroxymethyl)butyl]guanine (2) the plane of the acyclic N9 substituent is orthogonal to the purine ring. In crystals of 2 there is an extensive network of intermolecular hydrogen bonds. In 9-[4-acetoxy-3-(acetoxymethyl)butyl]-2-aminopurine (3) characteristic changes in the geometry of the pyrimidine ring in comparison with 2 are observed. In crystals of the 2-aminopurine derivative 3 there is an absence of major hydrogen bonding interactions and there are π-π interactions between parallel overlapping pyrimidine moieties.

There is a great deal of literature available detailing the synthesis, chemistry, and structural studies of the complexes of (1) and (3) ligands. 1 The same cannot be said for compounds of (2). Ara...

N-(diphenylphosphino)diallylamine (1) is a potential tridentate ligand containing both phosphorus and olefinic donor sites. Its preparation is straightforward and involves the addition of chlorodip...

Whereas the number of functionalised tertiary phosphines, and to a lesser extent phosphites, has flourished in recent years, related systems bearing one (or more) P-N bonds are poorly developed. Here we describe a facile synthetic route to some new, potentially hemilabile, P,O-hybrids. These ligands are of particular interest for use in catalysis[1] and also as suitable precursors for further functionalisation.