Synthesis, structure and luminescence studies of heterometallic gold(I)-copper(I) and -silver(I) alkynyl clusters/aggregates.

A series of pentanuclear gold(I)-copper(I) and -silver(I) mixed-metal alkynyl complexes, [(n)Bu(4)N][Au(3)M(2)(C triple bond CC(6)H(4)R-p)(6)] [M = Cu, R = OMe, O(n)Bu, O(n)Hex, Me, Et; M = Ag, R = Et, O(n)Hex] have been synthesized. The complexes were found to be emissive both in the solid state and in fluid solutions. DFT calculations at the B3LYP level of theory were performed on [Au(3)M(2)(C triple bond CC(6)H(4)Me-p)(6)](-) (M = Cu, Ag) to provide an understanding on the electronic structure of the complexes.

Synthesis, photophysics, electrochemistry, theoretical, and transient absorption studies of luminescent copper(I) and silver(I) diynyl complexes. X-ray crystal structures of [Cu3(micro-dppm)3(micro3-eta1-C triple bond CC triple bond CPh)2]PF6 and [Cu3(micro-dppm)3(micro3-eta1-C triple bond CC triple bond CH)2]PF6.

A series of soluble trinuclear copper(I) and silver(I) complexes containing bicapped diynyl ligands, [M(3)(micro-dppm)(3)(micro(3)-eta(1)-C triple bond CC triple bond CR)(2)]PF(6) (M = Cu, R = Ph, C(6)H(4)-CH(3)-p, C(6)H(4)-OCH(3)-p, (n)C(6)H(13), H; M = Ag, R = Ph, C(6)H(4)-OCH(3)-p), has been synthesized and their electronic, photophysical, and electrochemical properties studied. The X-ray crystal structures of [Cu(3)(micro-dppm)(3)(micro(3)-eta(1)-C triple bond CC triple bond CPh)(2)]PF(6) and [Cu(3)(micro-dppm)(3)(micro(3)-eta(1)-C triple bond CC triple bond CH)(2)]PF(6) have been determined.

3[(dx2-y2,dxy)(pz)] excited state of binuclear copper(I) phosphine complexes: effect of copper-ligand and copper-copper interactions on excited state properties and photocatalytic reductions of the 4,4'-dimethyl-2,2'-bipyridinium ion in alcohols.

A comprehensive study of the structural and spectroscopic properties of two-, three-, and four-coordinate copper(I) complexes with aliphatic phosphine ligands is presented. All complexes described in this work are characterized by X-ray crystallography. The intramolecular Cu...Cu separations in [Cu2(dcpm)2]X2, [Cu2(dcpm)2-(CH3CN)2]X2, and [Cu2(dmpm)3]-(ClO4)2 (dcpm=bis(dicyclohexylphosphino)methane; dmpm=bis(dimethylphosphino)methane; X=ClO4- and PF6-) are in the range 2.639(2)-3.021(2) A. The anion...CuI interaction is weak, as evidenced by the nearest O...Cu separation of 2.558(6) A in [Cu2(dcpm)2](ClO4)2 and the closest Cu...F separation of 2.79(1) A in [Cu2(dcpm)2](PF6)2. The absorption bands of [Cu2(dcpm)2]X2 and [Cu2(dcpm)2(CH3CN)2]X2 (X=ClO4- and PF6-) at lambda max 307-311 nm in CH2Cl2 are assigned as 1[3d sigma* --> 4p sigma] transitions; this has been confirmed by resonance Raman spectroscopy. The triplet emissions in the visible region from these complexes exhibit long lifetimes and are sensitive to the environment. The lowest emissive excited state is tentatively ascribed as 3[(dx2-y2, dxy)(pz)] in nature. For [Cu2(dcpm)2]2+ salts in CH3CN, the emissive species is postulated to be [Cu2(dcpm)2(CH3CN)n]2+ (n > or = 3). Efficient photocatalytic reduction of MV2+ (4,4'-dimethyl-2,2'-bipyridinium) to MV+ in alcoholic solutions by using [Cu2(dcpm)2](PF6)2 or [Cu2(dppm)2(CH3CN)4](ClO4)2 (dppm=bis(diphenylphosphino)methane) as a catalyst has been observed. The addition of CH3CN or use of [Cu2(dmpm)3]-(ClO4)2 as a catalyst did not allow photocatalytic reduction processes to occur.

Organic triplet emissions of arylacetylide moieties harnessed through coordination to [Au(PCy(3))]+. Effect of molecular structure upon photoluminescent properties.

A family of mono- and binuclear Cy(3)P-supported gold(I) complexes containing various pi-conjugated linear arylacetylide ligands, including the two homologous series (Cy(3)P)Au(Ctbd1;CC(6)H(4))(n)()(-)(1)(Ctbd1;CPh) and (Cy(3)P)Au(Ctbd1;CC(6)H(4))(n)()Ctbd1;CAu(PCy(3)) (n = 1-4), have been prepared. X-ray crystal analyses revealed no intermolecular aurophilic interactions in their crystal lattice. The lowest-energy singlet transitions are predominately intraligand in nature and exhibit both phenyl and acetylenic (1)(pipi) character. Strong photoluminescence is detected in solid and solution states under ambient conditions, with lifetimes in the microsecond regime. For complexes with a single arylacetylide group, only phosphorescence from the arylacetylide (3)(pipi) state is observed. Vibrational spacings in the solid-state emission spectra can be attributed to a combination of phenyl ring deformation and symmetric phenyl ring and Ctbd1;C stretches. Additional delayed-fluorescence emission is recorded for complexes with multiple p-arylacetylide units, and this is attributed to a triplet-triplet annihilation process. The phosphorescence energy of these complexes are readily modified by altering the length of the conjugated arylacetylide system, while the intensity of phosphorescence relative to fluorescence decreases when the p-arylacetylide chain is elongated. Information regarding the nature and relative energies of arylacetylide singlet and triplet excited states has been derived from the two homologous series and extrapolated to polymeric arylacetylide species. The (3)(pipi) excited-state reduction potentials E degrees [Au(+)/Au] (Au = 1a, 2, and 4) are estimated to be -1.80, -1.28, and -1.17 V versus SSCE, respectively.

Syntheses, electronic absorption, emission, and ion-binding studies of platinum(III) C empty set N empty set C and terpyridyl complexes containing crown ether pendants.

A series of platinum (II) C empty set N empty set C complexes, [Pt(C empty set N empty set C) (L)] (HC empty set N empty set CH=2,6-diphenylpyridine (dppy); L=Ph(2)PB15C5 (1, B15C5=benzo[15]crown-5), Ph(2)PDMP (2, DMP=3,4-dimethoxyphenyl), pyCOA15C5 (3, A15C5=aza[15]crown-5), pyCON(CH(2)CH(2)OCH(3))(2) (4), pyC[triple bond]CB15C5 (5), pyC[triple bond]CDMP (6)) and terpyridyl complexes, [Pt(trpy)(L)](X)(2) (trpy=2,2':6',2''-terpyridine; L=Ph(2)PB15C5, X=OTf (7 a), PF(6) (7 b); X=PF(6), L=Ph(2)PDMP (8), pyC[triple bond]CB15C5 (9), and pyC[triple bond]CDMP (10)) have been successfully synthesized and characterized. The structures of 1, 3, and 7 a have been determined by X-ray crystallography. Excitation of complexes 1-6 in EtOH/MeOH (4:1 v/v) glass gave high-energy structured emission bands, assigned as derived from states of metal-perturbed intraligand (IL) origin. At higher concentrations, complexes 3-6 each displayed an additional, structureless emission band at 600-615 nm, with complexes 5 and 6 showing an obvious increase in the intensity of this emission band when the concentration was increased further. In dichloromethane at room temperature, complexes 3-6 showed, in addition to the high-energy emission at 490-505 nm, an extra, broad emission band at 620-625 nm when the concentration was increased. The emission origins of the low-energy band in glass and in fluid solutions are suggested to be derived from the ground-state oligomerization or aggregation process of the complexes. In the solid state at room temperature, complexes 1-6 each showed a broad, unstructured emission band at 560-600 nm, which was shifted to lower energy upon cooling to 77 K. On the other hand, the terpyridyl analogues 7-10 displayed intense vibronic-structured intraligand (IL) emissions at 460-472 nm in butyronitrile glass at 77 K. Solid-state samples of 9 and 10 displayed strong phosphorescence upon photoexcitation at 298 K and 77 K, tentatively assigned as derived from states of Pt(d pi)-->pi*(trpy) (3)MLCT origin(MLCT=metal-to-ligand charge transfer). The ion-binding properties of complexes 5 and 9 for Na(+), Ba(2+), and K(+) ions have been studied by UV/Vis spectrophotometric methods, and confirmed by ESI mass spectrometric studies. The ion-binding properties for Na(+) ions have also been probed by (1)H NMR experiments. For the same crown ether-containing ligand and the same metal ions, the neutral cyclometalated complexes gave larger binding constants than the positively charged terpyridyl analogues.

Novel intramolecular cyclopropanation reaction of unsaturated beta-keto esters.

[reaction: see text] Fused cyclopropane beta-keto esters are versatile intermediates for the synthesis of many biologically active natural products. Here we report a new intramolecular cyclopropanation reaction of unsaturated beta-keto esters. In the presence of I(2), Et(3)N, and Lewis acids such as Mg(ClO(4))(2) and Yb(OTf)(3), beta-keto esters 1 bearing various olefin substituents were transformed to fused cyclopropanes 2 in a highly stereospecific manner with moderate to good yields. The mechanism of the reaction was also investigated.

Luminescent homo- and heteropolynuclear platinum(II) chalcogenido aggregates based on [Pt2E2(P empty set N)4] units (E=S, Se).

A series of homodinuclear platinum(II) complexes containing bridging chalcogenido ligands, [Pt(2)(mu-E)(2)(P empty set N)(4)] (P empty set N=dppy, E=S (1), Se (2); P empty set N=tBu-dppy, E=S (3)) (dppy=2-(diphenylphosphino)pyridine, tBu-dppy=4-tert-butyl-2-(diphenylphosphino)pyridine) have been synthesized and characterized. The nucleophilicity of the [Pt(2)E(2)] unit towards a number of d(10) metal ions and complexes has been demonstrated through the successful isolation of a number of novel heteropolynuclear platinum(II)-copper(I), -silver(I), and -gold(I) complexes: [[Pt(2)(mu(3)-E)(2)(dppy)(4)](2)Ag(3)](PF(6))(3) (E=S (4); Se (5)) and [Pt(2)(dppy)(4)(mu(3)-E)(2)M(2)(dppm)]X(2) (E=S, M=Ag, X=BF(4) (6); E=S, M=Cu, X=PF(6) (7); E=S, M=Au, X=PF(6) (8); E=Se, M=Ag, X=PF(6) (9); E=Se, M=Au, X=PF(6) (10)). Some of them display short metal.metal contacts. These complexes have been found to possess interesting luminescence properties. Through systematic comparison studies, the emission origin has been probed.

Metal-metal interactions in dinuclear d(8) metal cyanide complexes supported by phosphine ligands. Spectroscopic properties and ab initio calculations of [M(2)(mu-diphosphine)(2)(CN)(4)] and trans-[M(phosphine)(2)(CN)(2)] (M = Pt, Ni).

Structural, spectroscopic properties on the dinuclear [M(2)(dcpm)(2)(CN)(4)] (M = Pt, 1a; Ni, 2a, dcpm = bis(dicyclohexylphosphino)methane) and [M(2)(dmpm)(2)(CN)(4)] (M = Pt, 1b; Ni, 2b, dmpm = bis(dimethylphosphino)methane) and the mononuclear trans-[M(PCy(3))(2)(CN)(2)] (M = Pt, 3; Ni, 4, PCy(3) = tricyclohexylphosphine) and theoretical investigations on the corresponding model compounds are described. X-ray structural analyses reveal Pt.Pt and Ni.Ni distances of 3.0565(4)/3.189(1) A and 2.957(1)/3.209(8) A for 1a/1b and 2a/2b, respectively. The UV-vis absorption bands at 337 nm (epsilon 2.41 x 10(4) dm(3) mol(-)(1) cm(-)(1)) for 1a and 328 nm (epsilon 2.43 x 10(4) dm(3) mol(-)(1) cm(-)(1)) for 1b in CH(2)Cl(2) are assigned to (1)(5d(sigma) --> 6p(sigma)) electronic transitions originating from Pt(II)-Pt(II) interactions. Resonance Raman spectroscopy of 1a, in which all the Raman intensity appears in the Pt-Pt stretch fundamental (93 cm(-)(1)) and overtone bands, verifies this metal-metal interaction. Complexes 1a and 1b exhibit photoluminescence in the solid state and solution. For the dinuclear nickel(II) complexes 2a and 2b, neither spectroscopic data nor theoretical calculation suggests the presence of Ni(II)-Ni(II) interactions. The intense absorption bands at lambda > 320 nm in the UV-vis spectra of 2a and 2b are tentatively assigned to d --> d transitions.

Synthesis, characterization, photophysical properties, and biological labeling studies of a series of luminescent rhenium(I) polypyridine maleimide complexes.

We report the synthesis, characterization, and photophysical properties of a series of rhenium(I) polypyridine maleimide complexes [Re(N-N)(CO)(3)(py-3-mal)](CF(3)SO(3)) [N-N = 1,10-phenanthroline, phen (1), 2,9-dimethyl-1,10-phenanthroline, 2,9-Me(2)-phen (2), 3,4,7,8-tetramethyl-1,10-phenanthroline, 3,4,7,8-Me(4)-phen (3), 4,7-diphenyl-1,10-phenanthroline, 4,7-Ph(2)-phen (4), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 2,9-Me(2)-4,7-Ph(2)-phen (5), 2,2'-biquinonine, biq (6); py-3-mal = N-(3-pyridyl)maleimide]. The X-ray crystal structure of complex 2 has been investigated. Upon excitation, the complexes exhibit intense and long-lived photoluminescence in fluid solutions at 298 K. The emission wavelengths range from 514 to 654 nm, and the emission lifetimes fall in the microsecond time scale. The luminescence is assigned to originate from a metal-to-ligand charge-transfer MLCT [dpi(Re) --> pi*(diimine)] triplet excited state. As the maleimide group can react with the sulfhydryl group to form a stable thioether moiety, these complexes have been used as thiol-specific luminescent labels for a thiolated oligonucleotide, glutathione, and bovine serum albumin and human serum albumin. The photoluminescence properties of the labeled biological species have also been investigated.

Synthesis, Spectroscopic Properties, and Reactivities of Bis(tosylimido)osmium(VI) Porphyrin Complexes. X-ray Crystal Structure of [Os(VI)(TPP)(NSO(2)C(6)H(4)-pCH(3))(2)] (TPP = Tetraphenylporphyrinato).

The bis(tosylimido)osmium(VI) porphyrins [Os(VI)(Por)(NTs)(2)] [Por = tetraphenylporphyrinato (TPP), meso-tetrakis(p-tolyl)porphyrinato (TTP), meso-tetrakis(4-chlorophenyl)porphyrinato (4-Cl-TPP), meso-tetrakis(4-methoxyphenyl)porphyrinato (4-MeO-TPP); Ts = tosyl] were prepared from the reactions of [Os(II)(Por)(CO)(MeOH)] with excess PhI=NTs in dichloromethane. The X-ray crystal structure of [Os(VI)(TPP)(NTs)(2)] has been determined. Crystal data for [Os(VI)(TPP)(NTs)(2)]: triclinic, space group P&onemacr; (No. 2), a = 10.836(3) Å, b = 12.067(4) Å, c = 19.647(6) Å, alpha = 94.05(3) degrees, beta = 93.88(3) degrees, gamma = 104.65(3) degrees, V = 2469(1) Å(3), Z = 2, R (R(w)) = 0.030 (0.038), goodness-of-fit = 1.19. The mean Os=NTs distance is 1.800 Å. The Os-N-S angles average 155.8 degrees. Reaction of [Os(VI)(TPP)(NTs)(2)] with triphenylphosphine gives Ph(3)P=NTs and [Os(II)(TPP)(PPh(3))(2)].

Synthesis of Bis(aliphatic amine)osmium(II), Bis(arylamido)osmium(IV), and Bis(imido)- and Oxo(imido)osmium(VI) Porphyrins.

The syntheses, characterization, and reactivity of a series of osmium porphyrins, Os(II)(Por)(H(2)NR)(2) [Por = dianions of octaethylporphyrinato (OEP), tetraphenylporphyrinato (TPP), meso-tetrakis(p-tolyl)porphyrinato (TTP), meso-tetrakis(4-chlorophenyl)porphyrinato (4-Cl-TPP), meso-tetrakis(3,4,5-trimethoxyphenyl)porphyrinato (3,4,5-MeO-TPP), R = (t)Bu; Por = TPP, R = (i)Pr], Os(II)(Por)(HNEt(2))(2) (Por = TPP, 3,4,5-MeO-TPP), Os(IV)(Por)(NHAr)(2) (Por = OEP, TPP, 3,4,5-MeO-TPP; Ar = Ph, 4-F-Ph), Os(VI)(Por)(N(t)Bu)(2) (Por = TPP, TTP, 4-Cl-TPP, 3,4,5-MeO-TPP), Os(VI)O(Por)(N(t)Bu) (Por = TPP, TTP, 4-Cl-TPP, 3,4,5-MeO-TPP), and Os(VI)O(Por)(4-F-PhN) (Por = TPP, 3,4,5-MeO-TPP) are described. The complexes Os(Por)(HNAr)(2) are prepared from the reactions of Os(Por)(N(2))(THF) with arylamines in aerobic tetrahydrofuran. Air oxidations of Os(Por)(H(2)N(t)Bu)(2) in tetrahydrofuran and in the presence of H(2)N(t)Bu give OsO(Por)(N(t)Bu) and Os(Por)(N(t)Bu)(2). The X-ray crystal structures of OsO(TTP)(N(t)Bu).EtOH and Os(4-Cl-TPP)(N(t)Bu)(2) have been determined. Crystal data for OsO(TTP)(N(t)Bu).EtOH: monoclinic, space group P2(1)/c, a = 13.546(6) Å, b = 23.180(3) Å, c = 16.817(3) Å, beta = 90.84(2) degrees, V = 5279.7(1.0) Å(3), Z = 4. Os(4-Cl-TPP)(N(t)Bu)(2): monoclinic, space group P2(1)/c, a = 11.046(2) Å, b = 18.380(3) Å, c = 23.640(4) Å, beta = 97.22(1) degrees, V = 4759.8(1.0) Å(3), Z = 4. The Os=O and Os=N(t)Bu distances in OsO(TTP)(N(t)Bu).EtOH are 1.772(7) and 1.759(9) Å, respectively. The Os=N(t)Bu distances in Os(4-Cl-TPP)(N(t)Bu)(2) average 1.775 Å. The imido angles range from 165.8(8) to 170.6(9) degrees. For the infrared spectra of these complexes, a discussion on the "oxidation state marker" band in the vicinity of 1000 cm(-)(1) is presented. The differences in the electronic properties of osmium porphyrins at various oxidation states are also described.