N-(2-Chloro-eth-yl)morpholine-4-carbox-amide.

The title compound, C7H13ClN2O2, synthesized by the reaction of 2-chloro-ethyl iso-cyanate and morpholine, crystallizes with four molecules in the asymmetric unit, which have similar conformations and comprise two pairs each related by approximate non-crystallographic inversion centres. Two of them have a modest orientational disorder of the 2-chloro-ethyl fragments [occupancy ratio of 0.778 (4):0.222 (4)]. In the crystal, mol-ecules are linked by N-H⋯O=C hydrogen bonds, forming three crystallographically different kinds of infinite hydrogen-bonded chains extending along [001].

A novel structural rearrangement reaction of dialkylated derivatives of [Pt2(µ-S)2(PPh3)4] involving Pt-C bond formation.

Reaction of [Pt(2)(µ-S)(2)(PPh(3))(4)] with the dialkylating agents ClCH(2)C(O)CH(2)Cl or ClCH(2)C(=NNHC(O)NH(2))CH(2)Cl gives the dicationic di-µ-thiolate complexes [Pt(2){µ-SCH(2)C(O)CH(2)S)(PPh(3))(4)](2+) or [Pt(2){µ-SCH(2)C(=NNHC(O)NH(2))CH(2)S}(PPh(3))(4)](2+), isolated as BPh(4)(-) salts and characterised by ESI mass spectrometry, NMR spectroscopy and single-crystal X-ray crystallography. Treatment of the complex [Pt(2){µ-SCH(2)C(O)CH(2)S)(PPh(3))(4)](2+), which contains a [6.6.4] bicyclic system, with hydroxide ions results in deprotonation of a CH(2) group and rearrangement of the resulting monocation, giving [Pt(2)(µ-SCH(2)C(O)CHS}(PPh(3))(4)](+), isolated as its PF(6)(-) salt. An X-ray structure determination shows the complex to have a novel rearranged [6.5.5] bicyclic system containing a Pt-S-Pt-S-C five-membered ring with a Pt-C bond. The alkyl ligand has a high trans-influence, manifest in a long trans Pt-P bond and small (1)J(PtP) coupling constant to the trans PPh(3) ligand. Reaction of [Pt(2)(µ-S)(2)(PPh(3))(4)] with the 2,4-dinitrophenylhydrazone derivative of 1,3-dichloroacetone leads to the closely related complex [Pt(2){µ-SCH(2)C(=NNHAr)CHS}(PPh(3))(3)Cl] [Ar = C(6)H(3)(NO(2))(2)] in which a PPh(3) ligand is substituted by a chloride.

Isopolyoxometalates derived from arylstibonic acids with "reverse-Keggin ion" structures based on [M(RSb)12O28] cores, M = Co(II) or Zn(II).

The preparations and structures are described of four new polyoxostibonates, [Co(p-MeC(6)H(4)Sb)(12)O(28){Co(H(2)O)(3)}(4)]Cl(2)·6H(2)O, [Co(p-ClC(6)H(4)Sb)(12)O(28){Co(H(2)O)(3)}(4)]Cl(2)·22H(2)O, (PhCH(2)NMe(3))(2)[Zn(p-ClC(6)H(4)Sb)(12)O(28)Zn(4)Cl(2.54)Br(1.46)]·8MeCN·H(2)O and [BaCoH(4)(p-MeC(6)H(4)Sb)O(28)]·5H(2)O. Each of these has a framework of 12 (RSb) groups linked by 28 O atoms, with one transition metal ion in a tetrahedral site in the centre. Other metal ions are coordinated to the polyhedral faces. Three of the complexes have the ε Keggin ion geometry, while the fourth is a δ isomer.

Conversion of C[triple bond]C to CO in alkynyl-metal complexes: oxidation of carbon chains capped by carbon-tricobalt clusters.

Treatment of Co(3)(mu(3)-CC[triple bond]CR)(mu-dppm)(CO)(7) with O(2) (air) in the presence of [FcH]PF(6) afforded Co(3){mu(3)-CC(O)R}(mu-dppm)(CO)(7) by the formal conversion -C[triple bond]C- + O-O --> >C-O + C[triple bond]O. In this way, complexes with R = Ph, Fc, and W(CO)(3)Cp, bis-clusters {Co(3)(mu-dppm)(CO)(7)}(2){mu(3):mu(3)-[[triple bond]C(O)(C[triple bond]C)C[triple bond]]}, {Co(3)(mu-dppm)(CO)(7)}(2){mu(3):mu(3)-[[triple bond]C(O)(C[triple bond]C)(x)C(O)C[triple bond, length as m-dash]]} (x = 1, 2), and {Co(3)(mu-dppm)(CO)(7)}(2){mu(3):mu(3)-[[triple bond]CC(O)C[triple bond, length as m-dash]CC(6)H(4)C[triple bond]CC(O)C[triple bond]]}, and heterometallic bis-clusters {Co(3)(mu-dppm)(CO)(7)}{mu(3):mu(3)-[[triple bond]CC(O)C[triple bond]CC[triple bond]]}{M(3)(mu-H)(3)(CO)(9)} (M = Ru, Os) have been prepared. Single-crystal XRD structure determinations of several products are reported together with that of precursor {Co(3)(mu-dppm)(CO)(7)}(2){mu(3):mu(3)-[[triple bond]C(C[triple bond]C)(2)C(6)H(4)(C[triple bond]C)(2)C[triple bond]]}.

Cycloaurated triphenylphosphine-sulfide and -selenide.

The first examples of cycloaurated phosphine sulfides and triphenylphosphine selenide have been synthesised; these complexes are fairly rare examples of gold(iii) complexes with potentially reducing sulfur- and selenium-donor ligands. The cycloaurated complex (AuCl(2)(2-C(6)H(4)P(S)Ph(2)) was synthesised in good yield by transmetallation of the organomercury precursor Hg(2-C(6)H(4)P(S)Ph(2))(2) with Me(4)N[AuCl(4)]. A route to the chloro-mercury analogue ClHg(2-C(6)H(4)P(S)Ph(2)) was developed by reaction of the cyclomanganated triphenylphosphine sulfide (CO)(4)Mn(2-C(6)H(4)P(S)Ph(2)) with HgCl(2); this mercury substrate was also used in the synthesis of AuCl(2)(2-C(6)H(4)P(S)Ph(2)). The cycloaurated triphenylphosphine selenide complex AuCl(2)(2-C(6)H(4)P(Se)Ph(2)) was synthesised by an analogous methodology using the new phosphine selenide Hg(2-C(6)H(4)P(Se)Ph(2))(2) [prepared from Hg(2-C(6)H(4)PPh(2))(2) and elemental Se under sonication]. The phosphonamidic analogue AuCl(2)(2-C(6)H(4)P(S)(NEt(2))(2)) has also been synthesised from PhP(S)(NEt(2))(2)via lithiation and mercuration. X-Ray crystal structures of several compounds are reported, and show the presence of puckered ring systems.

Arylstibonic acids [H8(RSb)12O28]; precursors to organometallic isopolyoxostibonates [Na2H9(RSb)12O(30)]-, (R = aryl).

Electrospray ionisation mass spectrometry shows that arylstibonic acids, RSbO(3)H(2), give rise to oxo-bridged clusters derived from [H(8)(RSb)(12)O(28)] which act as inorganic crown ligands towards Na(+) cations; structure determination of one derivative revealed a cage-like anion [Na(2)H(9)(p-O(2)NC(6)H(4)Sb)(12)O(30).4H(2)O](-).

Tricyanovinylalkynyl-metal complexes: synthesis and some reactions.

Reactions of Group 8 metal ethynyls with tetracyanoethene afford tricyanovinylethynyl-metal derivatives, M{C[triple bond]CC(CN)=C(CN)(2)}(PP)Cp' [2; M = Ru, Os; PP = (PPh(3))(2), dppe; Cp' = Cp, Cp*; not all combinations]; a similar reaction occurs with the vinylidene RuCl(=C=CHPh)(PPh(3))Cp. Further replacement of a CN group in occurs with nucleophiles, while homo- and hetero-metallic derivatives are obtained by coordination of one of the remaining CN groups to other metal-ligand fragments.

Ruthenium and osmium carbonyl clusters incorporating stannylene and stannyl ligands.

The reaction of [Ru(3)(CO)(12)] with Ph(3)SnSPh in refluxing benzene furnished the bimetallic Ru-Sn compound [Ru(3)(CO)(8)(mu-SPh)(2)(mu(3)-SnPh(2))(SnPh(3))(2)] which consists of a SnPh(2) stannylene bonded to three Ru atoms to give a planar tetra-metal core, with two peripheral SnPh(3) ligands. The stannylene ligand forms a very short bond to one Ru atom [Sn-Ru 2.538(1) A] and very long bonds to the other two [Sn-Ru 3.074(1) A]. The germanium compound [Ru(3)(CO)(8)(mu-SPh)(2)(mu(3)-GePh(2))(GePh(3))(2)] was obtained from the reaction of [Ru(3)(CO)(12)] with Ph(3)GeSPh and has a similar structure to that of as evidenced by spectroscopic data. Treatment of [Os(3)(CO)(10)(MeCN)(2)] with Ph(3)SnSPh in refluxing benzene yielded the bimetallic Os-Sn compound [Os(3)(CO)(9)(mu-SPh)(mu(3)-SnPh(2))(MeCN)(eta(1)-C(6)H(5))] . Cluster has a superficially similar planar metal core, but with a different bonding mode with respect to that of . The Ph(2)Sn group is bonded most closely to Os(2) and Os(3) [2.786 and 2.748 A respectively] with a significantly longer bond to Os(1), 2.998 A indicating a weak back-donation to the Sn. The reaction of the bridging dppm compound [Ru(3)(CO)(10)(mu-dppm)] with Ph(3)SnSPh afforded [Ru(3)(CO)(6)(mu-dppm)(mu(3)-S)(mu(3)-SPh)(SnPh(3))] . Compound contains an open triangle of Ru atoms simultaneously capped by a sulfido and a PhS ligand on opposite sides of the cluster with a dppm ligand bridging one of the Ru-Ru edges and a Ph(3)Sn group occupying an axial position on the Ru atom not bridged by the dppm ligand.

Cycloauration of pyridyl sulfonamides.

The pyridyl-2-alkylsulfonamides C(5)H(4)N(CH(2))(n)NHSO(2)R (n = 1,2; R = Me, Ph or p-C(6)H(4)Me) and 8-(p-tosylamino)quinoline undergo facile cycloauration reactions with H[AuCl(4)] in water, giving metallacyclic complexes coordinated through the pyridyl (or quinolyl) nitrogen atom and the deprotonated nitrogen of the sulfonamide group. The complexes have been fully characterised by NMR spectroscopy, ESI mass spectrometry and elemental analysis. The X-ray crystal structures of two derivatives reveal the presence of non-planar sulfonamide nitrogen atoms. The complexes show low activity against P388 murine leukaemia cells, possibly as a result of their ease of reduction with mild reducing agents.

Syntheses, structures and redox properties of some complexes containing the Os(dppe)Cp* fragment, including [{Os(dppe)Cp*}2(mu-C triple bondCC triple bond C)].

The sequential conversion of [OsBr(cod)Cp*] (9) to [OsBr(dppe)Cp*] (10), [Os([=C=CH2)(dppe)Cp*]PF6 ([11]PF6), [Os(C triple bond CH)(dppe)Cp*] (12), [{Os(dppe)Cp*}2{mu-(=C=CH-CH=C=)}][PF6]2 ([13](PF6)2) and finally [{Os(dppe)Cp*}(2)(mu-C triple bond CC triple bond C)] (14) has been used to make the third member of the triad [{M(dppe)Cp*}2(mu-C triple bond CC triple bond C)] (M = Fe, Ru, Os). The molecular structures of []PF6, 12 and 14, together with those of the related osmium complexes [Os(NCMe)(dppe)Cp*]PF6 ([15]PF6) and [Os(C triple bond CPh)(dppe)Cp*] (16), have been determined by single-crystal X-ray diffraction studies. Comparison of the redox properties of 14 with those of its iron and ruthenium congeners shows that the first oxidation potential E1 varies as: Fe approximately Os < Ru. Whereas the Fe complex has been shown to undergo three sequential 1-electron oxidation processes within conventional electrochemical solvent windows, the Ru and Os compounds undergo no fewer than four sequential oxidation events giving rise to a five-membered series of redox related complexes [{M(dppe)Cp*}2(mu-C4)]n+ (n = 0, 1, 2, 3 and 4), the osmium derivatives being obtained at considerably lower potentials than the ruthenium analogues. These results are complimented by DFT and DT DFT calculations.

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

The reactivity of the metalloligand [Pt2(micro-S)2(PPh3)4] towards a variety of copper(II)-ligand systems has been studied. Reaction of [Pt2(mu-S)2(PPh3)4] with copper(II) halide complexes [CuCl2L](L = 2,2'-bipyridine and 1,10-phenanthroline) gave trinuclear dicationic products [Pt2(mu-S)2(PPh3)4CuL]2+, and the 8-hydroxyquinolinate (hq) complex [Cu(hq)2] gave [Pt2(mu-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(mu-S)2(PPh3)4] with CuCl2 and the amine. In contrast, reaction of [Pt2(mu-S)2(PPh3)4] with CuCl2 and NH3 in methanol gave the intensely blue methoxy-bridged dicopper complex [{Pt(2)(mu-S)2(PPh3)4Cu(OMe)}2]2+, isolated as its hexafluorophosphate salt. Copper beta-diketonate complexes reacted with [Pt2(mu-S)2(PPh3)4] giving [Pt2(mu-S)2(PPh3)4Cu(beta-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 beta-diketonate derivatives show varying stability towards methanolysis, giving [{Pt2(mu-S)2(PPh3)4Cu(OMe)}2]2+.

A low-toxicity method for the separation of lanosterol and dihydrolanosterol from commercial mixtures.

We describe an inexpensive, low-toxicity and high-yielding method for the production of pure lanosterol and dihydrolanosterol from the commercially available mixture. Optimum conditions are presented for the one-pot production of the intermediate 24,25 vicinal diol of lanosterol acetate (via either epoxidation or hydroxyhalogenation) which is readily separated from the unreacted dihydrolanosterol acetate. The lanosterol diol can then be converted to pure (>97%) lanosterol. Hypophosphorous acid was used for both the conversion of the epoxide to the diol, and as a catalyst for the hydroxyhalogenation by N-halosuccinimides of the olefinic bond.

Efficient routes to epimerically-pure side-chain derivatives of lanosterol.

A technically simple route is described to individual epimers of side-chain derivatives of lanosterol (3beta-hydroxy-5alpha-lanosta-8,24-diene). Epimerically pure 24,25-epoxy-, 24,25-dihydroxy- and 24-bromo-25-hydroxy-lanosterol have been prepared in good yield from commercial (50-60%) lanosterol. Hypophosphorous acid was used as a catalyst for the cohalogenation of the Delta24(25) bond and also for the efficient conversion of 24,25-epoxy- and 24-bromo-25-hydroxylanosterol to epimerically pure 24(R) or 24(S)-24,25-dihydroxylanosterols.

A novel methodology for the synthesis of complexes containing long carbon chains linking metal centres: molecular structures of [Ru(dppe)Cp*]2(mu-C14) and [Co3(mu-dppm)(CO)7]2(mu3:mu3-C16).

Elimination of AuX(PR3)(X = halogen, R = Ph, tol) occurs readily in reactions between compounds containing C(sp)- or C(sp2)-X bonds and alkynyl or polyynyl gold(I) complexes; this reaction has been applied to the syntheses of complexes containing a variety of metal centres linked by C(n) chains (n up to 16).

The pterocellins, novel bioactive alkaloids from the marine bryozoan Pterocella vesiculosa.

Two new alkaloids, pterocellins A and B, have been isolated from the New Zealand marine bryozoan Pterocella vesiculosa. Structural elucidation was achieved through NMR and mass spectral analysis in conjunction with a single-crystal X-ray diffraction study of pterocellin A. The pterocellins possess a novel heterocyclic skeleton and exhibit potent antitumor activity and antimicrobial activity in vitro but only modest activity in the in vivo hollow fiber assay at the National Cancer Institute.