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[Au(NH=C[Me.sub.2])P[Ph.sub.3]]Cl[O.sub.4] and [Ag(NH=C[Me.sub.2])[sub.2]]Cl[O.sub.4] can be used to prepare acetimino complexes of platinum. The species include the first cationic mono- and bis- (acetimino) complexes of Pt(II), the first Pt(IV) complexes with NH=C[R.sub.2] ligands, and the first heteronuclear mu-acetimido complexes of any metals.

The synthesis, structural characterization and luminescence properties of several gold(I) and gold(II) thiolate complexes are described. Gold(I) derivatives are luminescent in the solution state whereas mixed derivatives are not emissive, even when short gold(I)-gold(I) and gold(I)-gold(III) distances are present.

The preparation and characterization of the first series of platinum(II) complexes with (fluoren-9-ylidene)methanedithiolate and its 2,7-di-tert-butyl- and 2,7-dimethoxy-substituted derivatives and also the effect of the electron-donating character of the dithiolato ligands on their photoluminescence and reactivity are described. The oxidation and protonation reactions of the anionic complex with (2,7-di-tert-butyfluoren-9-ylidene)methanedithiolate, which lead to the formation of an unprecedented Pt(II)-Pt(IV) dithiolato complex or dithioato complexes, respectively, are presented.

The synthesis, structural characterization, emission properties, and reactivity of the first complexes of gold with (fluoren-9-xylidene)methanedithiolate and its 2,7-di-tert-bityl- and 2,7-bis(octyloxy)-substituted derivatives are presented. The reactivity and properties of the gold complexes described reveal the stronger electron-donating character of the new ligands.

The Selenolate gold compound reacts with aurophilic Au(I)-Au(I) and Au(I)-Au(III) derivatives to give polynuclear Au(I)-Au(I) and Au(I)-Au(III) complexes, with bridging selenolate ligands. These complexes have been characterized by using X-ray diffraction studies.

The features of coexistence of aurophilic interactions and the hydrogen bonds of the type N-H...F in complex M(C6F5){N(H)=CPh2}, where M=Ag or Au, is investigated by ab initio calculation at HR and MP2 level. Results revealed that the Au(l)-Au(l) interaction is stronger than Ag(l)-Ag(l) and that N-H...F hydrogen bonding and Au(l)-Au(l) contacts have similar strength in the same molecule.

Research has been conducted on [NBu (sub)4][AuR (sub)2], where R is C (sub)6 F (sub)5, C (sub)5 Cl (sub)5, complexes. The acid-base reaction between these complexes and thallium(I) hexafluorophosphate carried out in the presence of 4,4'-bipyridine has been investigated and the results of the structural analysis, synthesis and photophysical studies of the reaction are presented.

Research has been conducted on the 2,2-diacetyl-1,1-ethylenedithiolato palladium and platinum complexes. The use of these complexes as ligands in preparation of di-[MAg, MAu (M= Pd, Pt)], tri- [PdAg (sub)2, PtAg (sub)2, PtAu (sub)2, Pt (sub)2 M (M= Ni, Pt, Cd, Hg)] and tetranuclear (Pt (sub)2 Ag (sub)2, Pt (sub)2 Au (sub)2) complexes is described.

Crystallographic analysis demonstrates that among the third transition series element gold(III) and its derivatives of 2-(diphenylphosphino)-aniline, the compound gold(III)-N displays unusual reactivity and gold(I)-gold(III) interactions.

Results describe the synthesis and X-ray crystal structures of ortho, meta, and para isomers of [6,6]- and [8,8]cyclophanes bearing 1,4-dioxabut-2-yne and 1,6-dioxahexa-2,4-diyne bridges. Data on the cyclophanes' conformation and their cavity dimensions are used in semiemperical AM1 calculations to determine energy-minimized structures of cyclophanes.

Research has been conducted on the trinuclear gold(I) complexes. The synthesis and characterization of these complexes have been performed and the crystal structure of one of them has been determined via the X-ray diffraction studies.

2,2-diacetyl-1,1-ethylenedithiolato complexes of palladium and platinum and heterodimetallic 1,1-ethylenedithiolato complexes are described.

Substitution of the arsine ligands in [Au(sub 4){(PPh2)(sub 2)C2B9H10}(sub 2)(AsPh3)(sub 2)] by tertiary phosphines leads to the new cluster compounds [Au(sub 4){(PPh2)(sub 2)C2B9H10}(sub 2)(PR3)(sub 2)]. MP2 calculations indicate that the two types of chemically nonequivalent gold atoms are assigned as Au(I) and Au(O), the role of correlation in the gold-gold interactions are emphasized and the compounds are found by luminescent.

Research has been conducted on linear ferrocenyl phosphine gold(I) and silver(I) complexes. The use of X-ray diffraction in determining the crystal structure of the complexes is discussed.

Research has been conducted on the beta-diketonato complexes. The reaction of these complexes with an excess of CS (sub)2 has been investigated.

Research was conducted to examine a new mechanism for the preparation of upper-rim functionalized calix(4)arenes bearing distal P-containing substituents. It comprises the starting point for the synthesis of entire families of calixarenes having metals across the upper rim. The dinuclear rhodium complex was found to exhibit useful catalytic activity for the hydroformylation of olefins.

The ligand FcCHN(CH2)2SH (Fc = (eta(super 5)-C5H5)Fe(eta(super 5)-C5H4)) was prepared from the condensation reaction of ferrocenecarbaldehyde with beta-mercaptoethylamine. The ligand is easily oxidized to the disulfide derivative FcCHN(CH2)2S2(CH2)2NCHFc. Coordination of the gold centers occurs through the sulfur or nitrogen atoms. The crystal structure of (FcCHN(AuPPh3)(CH2)2S(AuPPh3)2)(TfO)2 revealed coordination of one gold(phosphine) fragment to the nitrogen and two fragments to the sulfur atom, as well as short gold-gold interactions.

The diastereoselective alkylation of suitably protected 3-substituted tetrahydroisoquinolines has been studied. The compound is readily available in enantiomerically pure form from L-phenylalanine by converting to the pure amino alcohol via Pictet-Spengler cyclization followed by reduction with LiAlH4. The diastereoselectivity is due to the steric bias from the bulky tert-butyldimethylsilyloxy group which directs the incoming electrophile to the opposite face.

Transannular metal-metal interactions in dinuclear coinage metal complexes were investigated. The dinuclear head-to-tail complexes (M2(PPh2CH2SPh)2)2+ (M = Cu, Ag, Au) were prepared either by reaction of (Cu(CH3CN)4)CF3SO3, AgClO4, AgCF3SO3, with equimolecular amounts of PPh2CH2SPh or of (AuCl(PPh2Ch2SPh)), prepared by reaction of (AuCl(tht)) and PPh2CH2SPh, with AgCF3SO3. Experimental results showed that metallophilic attraction exists for all the coinage metals as a correlation effect and is boosted in the case of gold by relativistic effects.

The substitution of the chlorine ligand to give [Au2X2(mu-dppf)] (X = Br, I) results from the reaction of [Au2Cl2(mu-dppf)] (dppf = 1,1'-bis(diphenylphosphino)ferrocene) with KX in acetone. The 31P{1H] NMR spectra indicate a singlet for the equivalent phosphorous atoms. Three multiplets with an intensity ratio 1:1:5 appear in the 1H NMR spectra. The crystal structure of [Au3(mu-3-Spy)(mu-dppf)(PPh2Me)](OTf)2 is the first example where a pyridinethiolate ligand bridges three gold atoms.

1H NMR studies were utilized to analyze the restricted rotation around the P-C bond in metalated phosphonium salts. Results indicated that the restricted rotation around the P-C bond in a series of complexes was shown to be restricted at room temperature or lower. The estimated values of deltaG* for the process lie in the range 67.3-42.2 kiloJoule*1/mol. Steric effects as well as electronic effects were strong determinants.

The complexes (Au(acac-kappaC2)(PR3)) (acac = acetylacetonate, R = Ph, C6H4OMe-4) react with (NH4)ClO4 to produce amminegold(I), (Au(NH3)(PR3))ClO4, amidogold(I), ((AuPR3)2(mu2-NH2))ClO4, or nitridogold(I), ((AuPR3)4(mu4-N))ClO4 complexes depending on the reaction conditions. Similarly, (Au(acac-kappaC2)(PPh3)) reacts with (NHeR')OTf (OTf = CF3SO3) (1:1) or with (H3N(CH2)2NH2)OTf (1:1) to produce (amine)gold(I) complexes.

The electrochemical behavior and reactivity of the tris-chelating hexadentate podand ligand tris{3-(2-pyridyl)(pyrazol-1-yl)}hydroborate (Tp(super Py)) was analyzed through electroparamagnetic resonance spectroscopic studies. An allosteric effect whereby a structural change at one site affected the properties of one site was evident on the electrochemical behavior of Cu(I)/Cu(II) oxidation. The oxidation resulted in a relative degree of disarrangement.

Compounds with a number of groups exopolyhedrally linked to the MCB10 cage system's metal atom are prepared with the use of a monocarbon metallacarborane with a closo-icosahedral framework as a reagent. The dimetal compounds (PtHgPh(PEt3)2(eta to the power of 5-7-CB10H11)) (3c), (3a, M = Au; 3b, M=Cu) and (PtM-(PEt3)2(PPh3)(eta to the power of 5-7-CB10H11)) are yielded by reactions with (HgC1Ph), (CuC1(PPh3))4 and (AuC1(PPh3)) respectively.

Organoselenolato compounds RSeMcp(CO)3 (M = Mo, W) with rare complexing properties were obtained from reactions of the organometallic selenolates Li(Na)SeMcp(CO)3 with allyl- or beta-methallyl chloride. Binuclear complexes of the form (cp(CO)3Mo(mu-SeR)M(CO)5) (M = Mo, W and R = CH2CHCH2, CH2C(CH3)CH2) as the main products were formed from the addition of W(CO)5(THF), (CH3CN)3Mo(CO)3, or (eta(super 6)-C7H8)Mo(CO)3. The crystal structures of five representative complexes are discussed.

A series of 2-propene- and 2-methyl-2-propeneselenolato complexes of molybdenum(II) and tungsten(II) were synthesized via oxidative addition reactions involving allyl and beta-methallyl chlorides. The synthetic process for the formation of the organometallic selenoates was characterized by the selenium insertion of carbonylates into alkali-metal-molybdenum and -tungsten bonds. Subsequent reactions with allylic chlorides led to the formation of 2-propene- and 2-methyl-2-propeneselenolato complexes which acted as ligands for unsaturated metal complex fragments.

The molecular structure of (1-hydroxyalkyl)dimethylphosphine sulfides were analyzed by nuclear magnetic resonance spectroscopy (NMR). The (1-hydroalkyl)dimethylphosphine sulfides exhibited centrosymmetric space groups due to the presence of racemate crystals containing conformational enantiomers. The sulfides are also stabilized by an anti conformational sulfur and oxygen that is located in the P-1-hydroxyalkyl bond with a nuclear magnetic shielding that is affected by intramolecular interactions.

The crystal structure of gold(I) complexes which were synthesized by the treatment of 1,2-dimercapto-o-carborane ligand with two equivalents of (AuClL) in the presence of Na2CO3 were elucidated using Siemens R3 or Stoe STADI-4 diffractometer. Among those examined, three complexes, (Au2(mu-S2C2B10H10)(PPh3)2), (Au2(mu-S2C2B10H10)(mu-((PPh2)2(CH=CH)))) and (Au2(mu-S2C2B10H10)(mu-((PPh2)2(C6H4)))), were found to have short gold-gold interactions.

The addition of iodine to tert-butyl(isopropyl)iodophosphane and t-Bu(i-Pr)PI3 led to the formation of t-Bu(i-Pr)PI3.25, t-Bu(i-Pr)PI4 and t-Bu(i-Pr)PI4.33. The reaction process is characterized by cation-anion interactions that are reduced by increasing iodine content. The t-Bu(isopropyl)phosphonium cations exhibited supramolecular chain helical and columnar structures with secondary soft-soft interactions that are dependent on the heavy atom interactions of neighboring substituents.

The hexadentate podand ligand tris(3-(2-pyridyl)pyrazolyl)hydroborate (Tp(super Py)) reacts with lanthanide (III) ions to give nine- or ten-coordinate 1:1 complexes (M(Tp(super Py))Ln)n+. The reaction can also form twelve coordinate 1:2 complexes (M(Tp(super Py)2))-(BPh4). The dissociation of nitrates of the 1:1 complexes in water and methanol permits solvent-based quenching. The quenching of the 12-coordinate complexes reveals the dissociation of one or more bidentate ligand arms to allow the solvent molecules into the coordination sphere.

X-ray structural measurements are used to analyze the coordination chemistry of several 2,2'-dipyridyl diselenide metal complexes containing neutral or ionic ligands. The results indicate that each of the metal complexes has four-membered rings derived from the chelating N-Se-coordination of the two 2-selenopyridines. These rings are coplanar with the adjacent pyridine rings.

The sulphur atom in the complex (S(Au2dppf)) can give trinuclear neutral (S(Au(C6F5))(Au2dppf)) or cationic derivatives (S(AuL)-(Au2dppf))ClO4 by coordinating neutral or cationic gold(I) fragments. The dppf in the compound is 1,1'-bis(diphenylphosphino)ferrocene and L is CH2PPh3, PPh3 or PPh2Me. Tri- and tetranuclear complex formation also occurs and they show short gold(I)-gold(I) interactions. The (S(AuL)4) monomer structure may be affected by the ligand attached to Au. Crystallographic data of the complexes obtained from nuclear magnetic resonance spectra analysis are given.

Na(sub 2)-2-thioxo-1,3-dithiole-4,5-dithiolate (Na2dmit) reacts with AuClPPh3 in 1:2 ratio to yield (Au2(dmit)L2) (L = PPh3 (1), PPh2Me (2), PMe3 (4), PPhMe2 (3), CH2PPh2Me (6). The compounds 1, 2 and 5 react with equimolar (AuL(tetrahydrothiophene))ClO4 to form Au3(dmit)L3)ClO4 complexes. The oxidation of these complexes with (TTF3)(sub 3-)(BF4)2 or electro-crystallization yields (TTF)2(Au(dmit)2), (TTF)(Au2(dmit)Br2), and (Au2(dmit)2(PPh3)). The resulting compounds exhibit mild conductivity as compacted pellets.

The AuCl(Pr3) reacted with 1,2-(Ph2P)2-1,2-C2B10H10 and yielded Au (PPh2)2C2B9H10 (PPh3) as one of its products. The product was protonated upon addition of NaH while further reaction with Au(PPh3)(tht) ClO4 resulted to the first metallocarborane compound Au2 (PPh2)2C2B9H9 (PPh3)2. The reaction of Au2Cl2(mu-P-P) with 1,2-(Ph2P)2-1,2-C2B10H10, on the other hand, yielded Au2 (PPh2)2C2B9H10 (sub 2) (mu-P-P) P-P=dppe=1,2-bis(diphenylphosphino)ethane, dppp=1,3-bis(diphenylphosphino)propane.

The synthesis and characterization of silicon-bridged macrocyclic compounds are presented. The scheme involves the reaction of carbo- and heterocyclic dianions with bis-electrophiles. Silicalix(4)arene was formed when p-tert-butylmethoxybenzene has been used as starting material. X-ray crystallographic studies of sicalix(4)arene conformers showed a partial cone conformation. Tests also indicate that the macrocycles extract metal ions with less affinity compared to crown ethers.

Platinum imidoyl phosphorus ylide complexes react with an ylide to produce a platinum complex containing an imidoyl phosphorus ylide ligand. Since the complexes have high reactivity to various bases, complex mixtures were produced. One of the compounds was refluxed with Na2CO3 to obtain pure midoyl phosphorus ylide complexes of platinum. The crystal structures of these complexes are presented.

Chain structures of Et2PI5(Et2PI2(super +)I3(super -))(sub x) and t-Bu2PI3(t-Bu2PI2(super +)I(super -))(sub x) are formed due to iodide-iodine interactions of acceptor iodine atoms of dialkyldiiodophosphonium cations, mu(sub 2)-bridging iodide and triiodide anions. Soft-soft interactions of cation-iodide are substantially higher compared to cation-triiodide interactions. The coordination of iodide anions with more acceptor atoms lengthens the I...I contacts.

Polychlorinated biphenyl (PCB) concentrations were observed in four UK urban centers from 1991-1992. The UK concentrations exhibited comparable properties with other urban areas on an international scale. The phenomenon of urban atmospheric PCB loading is attributed to several urban environment point sources and to a PCB building source. Building air and vegetation are observed as primary factors in urban air conditions.