113 results for Henderson, William, Journal article

  • Study of metal scrambling in the trinuclear {Pt₂Se₂M} (M = Pt, Pd, Au) system using an electrospray mass spectrometry (ESMS) directed synthetic methodology; isolation and crystallographic characterization of {Pt₂(µ₃-Se)₂(PPh₃)₄[Pt(cod)]}{PF₆}₂ and {Pt(μ₃-Se)₂(PPh₃)₂[Pt(cod)]₂}{PF₆}₂ (cod = Cyclo-octa-1,5-diene)

    Yeo, Jeremy S.L.; Vittal, Jagadese J.; Henderson, William; Hor, T.S. Andy (2002)

    Journal article
    University of Waikato

    Pt₂(μ-Se)₂(PPh₃)₄ reacts with PtCl₂(cod) to give {Pt₂(μ₃-Se)₂(PPh₃)₄[Pt(cod)]}²⁺ and an unexpected cod-rich product that arises from metal scrambling, viz. {Pt(μ₃-Se)₂(PPh₃)₂[Pt(cod)]₂}²⁺. The formation of these species was detected and followed by electrospray mass spectrometry (ESMS) and subsequently verified by batch synthesis and crystallographic characterization. Other metal-scrambled aggregate products were successfully detected.

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  • Use of cyclometallated PdCl[PPh₂CH₂CH₂CHCH₂CH₂PPh₂] as a precursor to homo and heterometallic species directed by ESMS (Electrospray Ionisation Mass Spectrometry)

    Neo, Kian Eang; Neo, Yew Chin; Chien, Sheau Wei; Tan, Geok Kheng; Wilkins, Alistair L.; Henderson, William (2004)

    Journal article
    University of Waikato

    The cyclometallated Pd compound PdCl[PPh₂CH₂CH₂CHCH₂CH₂PPh₂] 1, obtained from PdCl₂(Ph₂P(CH₂)₅PPh₂) in refluxing DMF (N,N-dimethylformamide), was characterized by NMR and X-ray single-crystal diffraction analysis. The cyclometallation of MCl₂(Ph₂P(CH₂)₅PPh₂)(M = Pd, Pt) to give 1 and its Pt(II) analogue was probed using electrospray ionisation mass spectrometry (ESMS). The reactivity of 1 towards neutral ligands such as phosphines and pyridines as well as basic metal complexes such as pyridine-thiolate compounds of Au(I), Hg(II) and Pt(II) in solution was also investigated. The results showed that the chloride trans to the Pd–C bond is susceptible to ligand replacement. A number of entry metalloligands was examined in an attempt to establish a route to cyclometallated aggregates and clusters.

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  • Self-assembly of a columnar polymeric calcium phosphinate derived from camphene

    Henderson, William; Leach, Meto T.; Nicholson, Brian K.; Sabat, Michal (1995)

    Journal article
    University of Waikato

    (2,2-Dimethylbicyclo[2.2.1] hept-3-ylmethyl)phosphinic acid (RPO₂H₂), readily prepared from camphene and hypophosphorous acid, formed a polymeric calcium salt [{Ca(RPO₂H) ₂ (RPO₂H₂)(H₂O)}n], with both terminal and triply bridging phosphinate groups, and an overall columnar structure with an inorganic core and a pseudo-close-packed sheath of terpene moieties.

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  • E/Z isomerism in monoalkylated derivatives of [Pt₂(μ-S)₂(PPh₃)₄] containing 2,4-dinitrophenylhydrazone substituents

    Ujam, Oguejiofo Theophilus; Devoy, Sarah M.; Henderson, William; Wilkins, Alistair L.; Nicholson, Brian K. (2011)

    Journal article
    University of Waikato

    Alkylation of [Pt₂(m-S)₂(PPh₃)₄] with 2,4-dinitrophenylhydrazone-functionalized alkylating agents XC6H4C{¼NNHC₆H₃(NO₂)₂}CH2Br (X¼H, Ph) gives monoalkylated cations [Pt₂(m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}C₆H₄X}(PPh₃)₄]⁺. An X-ray diffraction study on [Pt₂(m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}Ph}(PPh₃)₄]BPh₄ shows the crystal to be the Z isomer, with the phenyl ring and NHC₆H₃(NO₂)₂ groups mutually trans. ¹H- and ³¹P{¹H} NMR spectroscopic methods indicate a mixture of Z (major) and E (minor) isomers in solution, which slowly convert mainly to the E isomer. Reaction of [Pt₂(m-S)₂ (PPh₃)₄] with the dinitrophenylhydrazone of chloroacetone [ClCH₂C{¼NNH(C₆H₃(NO₂)₂}Me] and NaBPh₄ gives [Pt₂ (m-S){m-SCH₂C{¼NNHC₆H₃(NO₂)₂}Me}(PPh₃)₄]BPh₄, which exists as a single (E) isomer.

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  • Gold(III) thiosalicylate complexes containing cycloaurated 2-arylpyridine, 2-anilinopyridine and 2-benzylpyridine ligands

    Henderson, William; Nicholson, Brian K.; Faville, Suzanne J.; Fan, Daming; Ranford, John D. (2001-08-01)

    Journal article
    University of Waikato

    Reactions of the gold(III) dichloride complexes [(N_C)AuCl₂] ((N_C)=cycloaurated 2-phenylpyridine, 2-(p-tolyl)pyridine, 2-anilinopyridine or 2-benzylpyridine) with thiosalicylic acid (2-mercaptobenzoic acid, HSC₆H₄CO₂H) and base gives a series of gold(III) thiosalicylate complexes [(N_C)Au(SC₆H₄CO₂)]. A crystal structure determination on the 2-p-tolylpyridine derivative is reported, confirming the presence of a chelating thiosalicylate ligand, with the tolyl and thiolate groups mutually cis, together with a highly puckered gold–thiosalicylate moiety, and a twisted carboxylate group. The activity of the thiosalicylate complexes against P388 leukaemia cells has been determined.

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  • Isolation and X-ray structure of the platinum(II)–amidate complex cis-[PtCl{N(CO₂Et)C(O)CH₂CN}(PPh₃)₂], an intermediate in the silver(I) oxide-mediated synthesis of a platinalactam complex

    Henderson, William; Oliver, Allen G.; Nicholson, Brian K. (2000-01-01)

    Journal article
    University of Waikato

    The reaction of cis-[PtCl₂(PPh₃)₂] with one equivalent of N-cyanoacetylurethane, EtO₂CNHC(O)CH₂CN and silver(I) oxide, in dichloromethane at room temperature for short reaction times gives the complex cis-[PtCl{N(CO₂Et)C(O)CH₂CN}(PPh₃)₂] in high yield. This complex is an intermediate to the previously reported platinalactam complex [Pt{N(CO₂Et)C(O)CHCN}(PPh₃)₂]. The new complex was characterised by multinuclear NMR spectroscopy, electrospray mass spectrometry, and a single-crystal X-ray study. The deprotonated cyanoacetylurethane ligand lies in a plane almost perpendicular to the platinum coordination plane. Other metal oxides were studied in place of silver(I) oxide for the synthesis of the platinum amidate complex, but none were as successful as silver(I) oxide.

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  • Sulfide-bridged aggregates from the metalloligand [Pt₂(μ-S)₂(PPh₃)₄] and β-diketonate complexes of cobalt(II) and zinc(II)

    Bridson, James Hadley; Henderson, William; Nicholson, Brian K.; Hor, T.S. Andy (2006-01-01)

    Journal article
    University of Waikato

    Reaction of [Pt₂(μ-S)₂(PPh₃)₄] with a range of zinc(II) and cobalt(II) complexes ML₂, where L is a β-diketonate ligand CH₃COCHCOCH₃, PhCOCHCOPh, CF₃COCHCOTh (Th = 2-thienyl)] permits the synthesis of adducts [Pt₂(μ-S)₂(PPh₃)₄M(diketonate)]⁺, isolated as their BPH₄⁻salts in moderate yields. The cobalt and zinc acetylacetonate complexes were characterised by single-crystal X-ray diffraction studies, which reveal isomorphous structures, with tetrahedral heterometal centres.

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  • Organogold(III) complexes containing chelating bis(amidate) ligands: synthesis, characterization and biological activity

    Kilpin, Kelly Joan; Henderson, William; Nicholson, Brian K. (2007-01-01)

    Journal article
    University of Waikato

    Reactions of cycloaurated gold(III) dichloride complexes, with 1,2-C6H4(NHCOMe)2 and silver(I) oxide, or with C2H4(NHSO2Tol)2 (Tol = p-tolyl) or 1,2-C6H4(NHSO2Tol)2 and trimethylamine, give a series of new auracyclic complexes containing the Au-NR-CH2CH2-NR (R = SO2Tol) and Au-NR-C6H4-NR (R = COMe or SO2Tol) five-membered ring systems. An X-ray structure determination on (2-bp)Au{N(COMe)C6H4N(COMe)} (2-bp = cycloaurated 2-benzylpyridine) shows the presence of puckered metallacyclic rings, with both acetyl substituents positioned below the Au(III) coordination plane. The complex (2-bp)Au{N(COMe)C6H4N(COMe)} undergoes ring cleavage in the presence of halide and water, to give the complex (2-bp)Au{N(COMe)C6H4NH(COMe)}Cl, which was characterised crystallographically, and shown to contain a monodentate amidate ligand. Biological activity studies of the new auracyclic complexes are also reported, against P388 murine leukaemia cells and a range of bacteria and fungi, with a number of complexes showing high activity.

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  • Synthesis, characterization and biological activity of cycloaurated organogold(III) complexes with imidate ligands

    Kilpin, Kelly Joan; Henderson, William; Nicholson, Brian K. (2007-01-01)

    Journal article
    University of Waikato

    The reactions of the cycloaurated gold(III) complexes (2-bp)AuCl2 (2-bp = 2-benzylpyridyl) or (damp)AuCl2 (damp = Me2NCH2C6H4) with an excess of sodium saccharinate (Nasacc), potassium phthalimidate (Kphth), or with isatin and trimethylamine in refluxing methanol results in the successful isolation of a series of new gold(III) imidate complexes. These were characterised by NMR and IR spectroscopies, and by X-ray structure determinations on (2-bp)Au(sacc)2 and (2-bp)Au(phth)2. In both structures, the planes of the saccharinate and the phthalimidate ligands are orientated almost perpendicular to the gold coordination plane. As expected from trans-influence considerations, the Au-N(imidate) bond lengths trans to the aryl carbon atoms are longer than the Au-N(imidate) bond lengths trans to the pyridyl groups. The complexes have also been characterised by electrospray ionisation MS; in the presence of halide ligands, one imidate ligand is readily displaced. Anti-tumour (P388 murine leukemia) and selected anti-microbial data for the new complexes are reported. Surprisingly, all three damp complexes had low anti-tumour activity, which is likely to be a consequence of the poor solubility of these complexes. The synthesis and characterisation of a related gold(III) bis(amidate) complex derived from sulfathiazole is also described.

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  • Hydrogen-bonded adducts formed from platinum(II) and palladium(II) thiosalicylate complexes [(Ph₃E)₂M(SC₆H₄CO₂)] (E=P, As) and triethylammonium or pyridinium ions; X-ray crystal structure of [(Ph₃P)₂Pt(SC₆H₄CO₂) HNEt₃]⁺[BPh₄]⁻

    Henderson, William; Nicholson, Brian K. (2003-03-01)

    Journal article
    University of Waikato

    One-pot reactions of [MCl₂(cod)] (cod=cyclo-octa-1,5-diene; M=Pt, Pd) with two equiv of PPh₃ or AsPh₃, one equiv of thiosalicylic acid, and an excess of triethylamine base, followed by the addition of excess Na[BPh₄] to the hot reaction mixture gives complexes [(Ph₃E)₂M(SC₆H₄CO₂) HNEt₃]⁺[BPh4]⁻ (E=P, As). Analogous pyridinium and platinum–thioglycolate [(Ph₃P)₂Pt(SCH₂CO₂)] derivatives were also prepared. An X-ray crystal structure determination on [(Ph₃P)₂Pt(SC₆H₄CO₂) HNEt₃]⁺[BPh₄]⁻ reveals hydrogen-bonding between the NH proton and the carbonyl group of the thiosalicylate ligand, the major effect of which is to flatten the platinum–thiosalicylate moiety. NMR spectroscopic data indicate that the hydrogen-bonding interaction persists in solution.

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  • Synthesis and crystal structure of the first complex containing a chelating selenourea dianion ligand

    Nicholson, Brian K.; Henderson, William; Dinger, Maarten B. (2003-11-01)

    Journal article
    University of Waikato

    Reaction of N,N′-diphenylselenourea, PhNHC(Se)NHPh, with cis-[PtCl2(PPh3)2] and triethylamine in hot methanol gives the first example of a selenourea dianion complex, [Pt{SeC(=NPh)NPh}(PPh3)2] isolated as a yellow solid in high yield. The structure of the complex was determined by X-ray crystallography and found to be similar to the related thiourea dianion complex [Pt{SC(=NPh)NPh}(PPh3)2], with a Pt---Se---C---N four-membered ring. The antitumour activity (P388 murine leukaemia cells) of the selenourea dianion complex was determined, together with a small selection of related platinum(II)-thiourea dianion complexes (prepared by an analogous method) for comparison. The complex [Pt{SC(=NMe)NMe}(PPh3)2] showed high activity [IC50 1.0 μM], with the other complexes showing moderate to low activity.

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  • Synthesis and characterisation of four- and eight-membered ring auralactam complexes

    Henderson, William; Nicholson, Brian K.; Oliver, Allen G. (2001-02-01)

    Journal article
    University of Waikato

    The reactions of the cyclo-aurated gold(III) dihalide complex [{C6H3 (CH2NMe2)-2-(OMe)-5}AuCl2] with N-cyanoacetylurethane [NCCH2C(O)NHCO2Et], 2-benzoylacetanilide [PhC(O)CH2C(O)NHPh] and acetoacetanilide [MeC(O)CH2C(O)NHPh], and [{C6H4 (CH2NMe2)-2}AuCl2] with acetoacetanilide in dichloromethane with excess silver(I) oxide gives the first examples of auralactam complexes, containing Au-NR-C(O)-CHR′ four-membered rings. A single-crystal X-ray diffraction study on the complex [{C6H4 (CH2NMe2)-2}Au{NPhC(O)CH(COMe)}] reveals similar structural features to related metallalactam complexes of platinum(II) and palladium(II). When a CDCl3 solution of the complex [{C6H3 (CH2NMe2)-2-(OMe)-5}Au{N(CO2Et)C(O)CHCN}] is allowed to stand for 18 h, a novel dimerisation reaction occurs, giving the insoluble product [{C6H3 (CH2NMe2)-2-(OMe) 5}Au{N(CO2Et)C(O)CHCN}]2 2CDCl3, characterised by an X-ray structure determination. The dimer contains an eight-membered Au-N-C(O)-C-Au-N-C(O)-C ring.

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  • Syntheses and ligand interconversions of copper(II) derivatives of the metalloligand [Pt₂(µ-S)₂(PPh₃)₄]

    Devoy, Sarah M.; Henderson, William; Nicholson, Brian K.; Fawcett, John; Hor, T.S. Andy (2005-07-01)

    Journal article
    University of Waikato

    The reactivity of the metalloligand [Pt₂(µ-S)₂(PPh₃)₄] towards a variety of copper(II)–ligand systems has been studied. Reaction of [Pt₂(µ-S)₂(PPh₃)₄] with copper(II) halide complexes [CuCl₂L](L = 2,2 -bipyridine and 1,10-phenanthroline) gave trinuclear dicationic products [Pt₂(µ-S)₂(PPh₃)₄CuL]²⁺, and the 8-hydroxyquinolinate (hq) complex [Cu(hq)₂] gave [Pt₂(µ-S)₂(PPh₃)₄Cu(hq)]⁺, isolated as their BPh₄⁻ or PF₆⁻ salts. Related cationic complexes with other ancillary amine ligands (1,2-diaminoethane, 1,2-diaminopropane, 1,2-diaminocyclohexane) were obtained by reactions of [Pt₂(µ-S)₂(PPh₃)₄] with CuCl2 and the amine. In contrast, reaction of [Pt₂(µ-S)₂(PPh₃)₄] with CuCl₂ and NH₃ in methanol gave the intensely blue methoxy-bridged dicopper complex [{Pt₂(µ-S)₂(PPh₃)₄Cu(OMe)}₂]²⁺, isolated as its hexafluorophosphate salt. Copper β-diketonate complexes reacted with [Pt₂(µ-S)₂(PPh₃)₄] giving [Pt₂(µ-S)₂(PPh₃)₄Cu(β-diketonate)]⁺PF₆⁻ complexes, with the CH₃COCHCOCH₃(acac) and CF₃COCHCO(2-thienyl)(tta) derivatives characterised by X-ray structure determinations. The local Cu(II) environment ranges from distorted square-planar to an intermediate form of square-planar and tetrahedral. The β-diketonate derivatives show varying stability towards methanolysis, giving [{Pt₂(µ-S)₂(PPh₃)₄Cu(OMe)}₂]²⁺.

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  • Camphene-derived primary and hydroxymethyl phosphines

    Berrigan, Rebecca A.; Russell, Douglas K.; Henderson, William; Leach, Meto T.; Nicholson, Brian K.; Woodward, Gary; Harris, Christopher (2001-01-01)

    Journal article
    University of Waikato

    Thermal disproportionation of (2,2-dimethylbicyclo[2.2.1]hept-3-ylmethyl)phosphinic acid (endo-8-camphanylphosphinic acid, camPO₂H₂) yields the primary phosphine (2,2-dimethylbicyclo[2.2.1]hept-3-ylmethyl)phosphine (camPH₂). The compound has been characterised by NMR spectroscopy, and as its tris(hydroxymethyl)phosphonium chloride salt [camP(CH₂OH)₃]Cl, synthesised by reaction with excess formaldehyde and hydrochloric acid. The X-ray crystal structure of this phosphonium salt is reported, confirming the endo position of the phosphonium group. On treatment with triethylamine base, camP(CH₂OH)₃ ⁺Cl⁻ is converted to the hydroxymethylphosphine camP(CH₂OH)₂. The sulfide and selenide of this phosphine have been prepared, together with the platinum(II) complex cis-[PtCl₂{camP(CH₂OH)₂}₂]. The gas-phase decomposition of camPH₂ has been investigated using the technique of IR laser powered homogeneous pyrolysis. Results indicate the initial elimination of phosphine, followed by the rearrangement and decomposition of camphene through two distinct pathways.

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  • Platinum(II) complexes of chelating and monodentate thiourea monoanions incorporating chiral, fluorescent or chromophoric groups

    Henderson, William; Nicholson, Brian K.; Rickard, Clifton E.F. (2001-08-01)

    Journal article
    University of Waikato

    The reaction of cis-[PtCl2(PPh3)2] with trisubstituted thioureas [R1R2NC(=S)NHR3] in refluxing methanol with triethylamine base, followed by addition of NaBPh4 gives the salts [Pt{SC(=NR1R2)NR3}(PPh3)2]BPh4 in high yield; a range of thiourea substituents, including chiral, fluorescent and chromophoric groups can be incorporated. The azo dye-derived complex [Pt{SC(=N(CH2CH2)2O)NC6H4N=NC6H4NMe2}(PPh3)2]BPh4 has been characterised by a single-crystal X-ray diffraction study. The formation of a fluorescein-derivatised platinum-thiourea complex is also described. Reaction of cis-[PtCl2(PPh3)2] with PhNHC(S)NHPh or EtNHC(S)NHEt, triethylamine and NaBPh4 gives, respectively, [Pt{SC(=NHPh)NPh}(PPh3)2]+ and the known cation [Pt{SC(=NHEt)NEt}(PPh3)2]+, isolated as tetraphenylborate salts. Reaction of cis-[PtCl2(PPh3)2] with an excess of Na[MeNHC(S)NCN] in methanol gives the bis(thiourea monoanion) complex trans-[Pt{SC(=N---CN)NHMe}2(PPh3)2], characterised by NMR spectroscopy and an X-ray crystal structure determination. When cis-[PtCl2(PPh3)2] is reacted with 1 equiv. of Na[MeNHC(S)N---CN] in methanol, with added NaBPh4, a mixture of isomers of the [Pt{SC(=NHCN)NMe}(PPh3)2]+ cation is obtained.

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  • Heterobimetallic platinum–bismuth aggregates derived from [Pt₂(μ-S)₂(PPh₃)₄]

    Henderson, William; Nicholson, Brian K.; Zhang, Hao; Hor, T.S. Andy (2006-01-01)

    Journal article
    University of Waikato

    The metalloligand [Pt₂(μ-S)₂(PPh₃)₄] reacts with Bi(S₂CNEt₂)₃ or Bi(S₂COEt)₃ in methanol to produce the orange cationic adducts [Pt₂(μ-S)₂(PPh₃)₄Bi(S₂CNEt₂)₂]⁺ and [Pt₂(μ-S)₂(PPh₃)₄Bi(S₂COEt)₂]⁺, respectively, isolated as their hexafluorophosphate salts. An X-ray structure determination on [Pt₂(μ-S)₂(PPh₃)₄Bi(S₂CNEt₂)₂]PF₆ reveals the presence of a six-coordinated bismuth centre with an approximately nido-pentagonal bipyramidal coordination geometry. Fragmentation pathways for both complexes have been probed using electrospray ionisation mass spectrometry; ions [Pt₂(μ-S)₂(PPh₃)₂Bi(S₂CXEtn)₂]⁺ (X = O, n = 1, X = N, n = 2) are formed by selective loss of two PPh₃ ligands, and at higher cone voltages the species [(Ph₃P)PtS₂Bi]⁺ is observed. Ions formed by loss of CS₂ are also observed for the xanthate but not the dithiocarbamate ions.

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  • Hydrogen bonding in hydroxymethylphosphine chalcogenides

    Goodwin, Nicholas J.; Henderson, William; Nicholson, Brian K. (2002-06-01)

    Journal article
    University of Waikato

    Hydrogen bonding in the phosphine chalcogenide series Ph2P(X)CH2OH (X=O, 1; S, 2; Se, 3) has been investigated by single crystal X-ray crystallography. While the phosphine oxide exhibits a dimer motif, the sulfide and selenide form infinite chains; in all cases hydrogen bonding is from the OH group to the phosphine chalcogenide heteroatom. The trend in the hydrogen bond angle for OH X-P, which is 117, 87 and 84° for the oxide, sulfide and selenide, respectively, is explained with respect to the geometry of electron density on the phosphine chalcogenide heteroatom.

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  • Moderating the nucleophilicity of the sulfide ligands in the dinuclear {Pt₂S₂} metalloligand system using triphenylarsine

    Jeram, Sunita; Henderson, William; Nicholson, Brian K.; Hor, T.S. Andy (2006-06-01)

    Journal article
    University of Waikato

    Reaction of cis-[PtCl₂(AsPh₃)₂] with excess sodium sulfide in benzene gave the triphenylarsine analogue of the well-known metalloligand [Pt₂(μ-S)₂(PPh₃)₄] as an orange solid.The compound was characterised by detailed mass spectrometry studies, and by conversion to various alkylated and metallated derivatives.The sulfide ligands in [Pt₂(μ-S)₂(AsPh₃)₄] are less basic than the triphenylphosphine analogue, and the complex gives a relatively weak [M+H]⁺ ion in the positive-ion electrospray (ESI) mass spectrum, compared with the phosphine analogue.Methylation of an equimolar mixture of [Pt₂(μ-S)₂(PPh₃)₄] and [Pt₂(μ-S)₂(AsPh₃)₄] with MeI gave the species [Pt₂(μ-S)(μ-SMe)(AsPh₃)₄]⁺ and [Pt₂(μ-SMe)₂(PPh₃)₃I]⁺, indicating a reduced tendency for the sulfide of [Pt₂(μ-S)(μ-SMe)(AsPh₃)₄]⁺ to undergo alkylation.The lability of the arsine ligands is confirmed by the reaction of an equimolar mixture of [Pt₂(μ-S)₂(PPh₃)₄] and [Pt₂(μ-S)₂(AsPh₃)₄] with n-butyl chloride, giving [Pt₂(μ-S)(μ-SBu)(Eph₃)₄] (E = P, As), which with Me₂SO₄ gave a mixture of [Pt₂(μ-SMe)(μ-SBu)(PPh₃)₄]²⁺ and [Pt₂(μ-SMe)(μ-SBu)(AsPh₃)₃Cl]⁺.Reactivity towards 1,2-dichloroethane follows a similar pattern.The formation and ESI MS detection of mixed phosphine–arsine {Pt₂S₂} species of the type[Pt₂(μ-S)₂(AsPh₃)n(PPh₃)4−n] is also discussed. Coordination chemistry of [Pt₂(μ-S)₂(AsPh₃)₄] towards a range of metal-chloride substrates, forming sulfide-bridged trinuclear aggregates, has also been probed using ESI MS, and found to be similar to the phosphine analogue. The X-ray crystal structure of [Pt₂(μ-S)₂(AsPh₃)₄Pt(cod)](PF₆)₂ (cod = 1,5-cyclo-octadiene) has been determined for comparison with the (previously reported) triphenylphosphine analogue. ESI MS is a powerful tool in exploring the chemistry of this system; in some cases the derivatising agent p-bromobenzyl bromide is used to convert sparingly soluble and/or poorly ionising {Pt₂S₂} species into soluble, charged derivatives for MS analysis.

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  • Synthesis and X-ray structures of triphenylphosphine-mercury(II) thiosalicylate complexes: novel aggregation processes

    Nicholson, Brian K.; Henderson, William (2002-06-01)

    Journal article
    University of Waikato

    Reaction of [HgCl2(PPh3)2] with one equivalent of thiosalicylic acid (tsalH2, HSC6H4CO2H) and excess triethylamine, followed by recrystallisation from dichloromethane-diethyl ether gives the compound [Hg2(tsal)2(PPh3)2] (2). This has a bis(S,O)-chelated mercury centre with a nido-trigonal bipyramidal coodination, with the four oxygens of the two carboxylates also coordinated to a Hg(PPh3)2 moiety. When a reduced quantity of pyridine was used as the base a different crystalline product was isolated. This was characterised as [Hg2(tsal)2(PPh3)2][Hg(tsalH)2] (3), which contains the same [Hg2(tsal)2(PPh3)2] moiety found for 2, co-crystallised with a [Hg(tsalH)2]. The two mercury-thiosalicylate species are connected by means of O-H O hydrogen bonding.

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  • Reactions of isonitriles with [Fe₃(CO)₁₂] and [Ru₃(CO)₁₂] monitored by electrospray mass spectrometry: structural characterisation of [Fe₃(CO)₁₀(CNPh)₂] and [Ru₄(CO)₁₁(μ₃-η²-CNPh)₂(CNPh)]

    Decker, Corry; Henderson, William; Nicholson, Brian K. (2004-05-01)

    Journal article
    University of Waikato

    The reactions of [Fe₃(CO)₁₂] or [Ru₃(CO) ₁₂] with RNC (R=Ph, C₆H₄OMe-p or CH₂SO₂C₆H₄Me-p) have been investigated using electrospray mass spectrometry. Species arising from substitution of up to six ligands were detected for [Fe₃(CO)₁₂], but the higher-substituted compounds were too unstable to be isolated. The crystal structure of [Fe₃(CO)₁₀(CNPh)₂] was determined at 150 and 298 K to show that both isonitrile ligands were trans to each other on the same Fe atom. For [Ru₃(CO)₁₂] substitution of up to three COs was found, together with the formation of higher-nuclearity clusters. [Ru₄(CO)₁₁(CNPh)₃] was structurally characterised and has a spiked-triangular Ru₄ core with two of the CNPh ligands coordinated in an unusual μ₃-η² mode. The substitution reactions of [M₃(CO)₁₂] by RNC have been investigated by electrospray mass spectrometry showing up to six COs can be replaced. [Fe₃(CO)₁₀(CNPh)₂] has both PhNC axially on the same Fe atom, and [Ru₄(CO)₁₁(μ₃-η²-CNPh)₂(CNPh)] has a spiked-triangular cluster core with two PhNC ligands in an unusual coordination mode.

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