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1.
Inorg Chem ; 62(37): 14998-15005, 2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37655478

RESUMO

Although ionic liquids (ILs) are of prime interest for the synthesis of various nanomaterials, they are scarcely utilized for the polyhydrido copper(I) [Cu(I)H] clusters. Herein, two air-stable Cu(I)H clusters, [Cu8H6(dppy)6](NTf2)2 (Cu8H6) and {Cu12H9(dppy)6[N(CN)2]3} (Cu12H9), are synthesized in high yields for the first time from the ILs-driven conversion of an unprecedented cluster [Cu7H5(dppy)6](ClO4)2 (Cu7H5) by a facile three-layers diffusion crystal (TLDC) method, strategically introducing IL-NTf2 and IL-N(CN)2 as two types of unusual interfacial crystallized templates, respectively. Their structures are fully characterized by various spectroscopic methods and X-ray crystallography, which shows that the anion of IL plays an important role as an anion template and an anion ligand in controlling the structural conversion of Cu(I)H clusters. Their photophysical properties are also investigated, and it is found that all reported clusters exhibit red luminescence with λem ranging from 600 to 690 nm.

2.
Phys Chem Chem Phys ; 23(26): 14276-14283, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34159984

RESUMO

Non-noble metal single-atom catalysts hold great promise in selective oxidation reactions, although the progress is still unsatisfactory because of the synthesis challenge and the lack of mechanistic interpretations. Herein, we develop a biomolecule-based strategy to synthesize isolated Co single atom site catalysts by one-step pyrolysis of guanosine and Co precursors. Due to the abundant hydrogen bonding and π-π interaction of guanosine, the as-synthesized Co-N-C catalysts present a hierarchical porous two-dimensional (2D) nanostructure with an ultrahigh specific surface area, large pore volume, and high density of cobalt single atoms. Aberration-corrected electron microscopy and X-ray photoelectron spectroscopy reveal that Co species are present as isolated single sites and stabilized by nitrogen-doped carbon nanosheets. These characteristics make Co-GS-900 suitable as an efficient catalyst for selective oxidation of aromatic alkanes. For oxidation of ethylbenzene, Co-GS-900 exhibits a superior performance f with 91% conversion and 98% selectivity of acetophenone.

3.
Chemistry ; 21(11): 4205-8, 2015 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-25580911

RESUMO

A heterometallic cluster [Ag6Au6(ethisterone)12] of an unprecedented topology was synthesized and characterized. A sensitive and specific probe for estrogen receptor α (ERα) has been developed for the first time based on the enhancement of the Ag6Au6 luminescence.


Assuntos
Receptor alfa de Estrogênio/metabolismo , Etisterona/metabolismo , Cobre , Ouro , Humanos , Luminescência
4.
Dalton Trans ; 53(13): 5844-5850, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38469690

RESUMO

Three pargyline-phosphine copper(I) clusters, [Cu4(CC-C9H12N)3(PPh3)4](PF6) (1) and [Cu6(CC-C9H12N)4(dppy)4](X)2 (dppy = diphenyl-2-pyridylphosphine; X = PF6 for 2 and X = ClO4 for 3), were synthesized. Their structures were fully characterized using various spectroscopic methods and X-ray crystallography, which showed that the stoichiometry and nature of pargyline and phosphine ligands play an important role in tuning the structure and photophysical features of Cu(I) clusters. Interestingly, clusters 1, 2 and 3 exhibited red, orange and yellow phosphorescence with high quantum yields of 88.5%, 22.0% and 40.2%, respectively, at room temperature. Moreover, clusters 1-3 show distinct temperature-dependent emissions. The excellent luminescence performance of 1 and 3 was designed and employed for the construction of monochrome and white light-emitting devices (LEDs).

5.
Dalton Trans ; 52(19): 6267-6272, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37083211

RESUMO

Developing low-cost and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) has stimulated extensive interest. Molybdenum carbide materials have been proposed as promising alternatives to noble platinum-based catalysts due to their earth abundance and tunable physicochemical characteristics. Here, we report Mo2C@NC/Mo2C hollow microspheres composed of a ß-Mo2C core and small ß-Mo2C particles embedded within a nitrogen-doped carbon shell and prepared using guanosine and hexaammonium molybdate as precursors via a hydrothermal self-assembly process, which results in outstanding catalytic activity and fast kinetics in hydrogen evolution in both acidic and alkaline solutions. The significant activity improvement of Mo2C@NC/Mo2C can be attributed to the large ratio of exposed active sites and abundant interfacial structures. This work provides a new template-free strategy for the design of a highly active Mo2C@NC/Mo2C hollow microsphere HER catalyst.

6.
Inorg Chem ; 51(20): 11117-25, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23016667

RESUMO

Two hexanuclear clusters, [Pt(2)Ag(4)(C≡CC(6)H(4)R)(8)] (R = CH(3), 1; R = H, 2), together with dimer [Pt(2)Ag(4)(C≡CC(6)H(5))(8)](2) (3), have been synthesized and characterized by elemental analyses, electrospray ionization mass spectrometry, and (1)H NMR spectroscopy and by X-ray crystallography for 1 and 3. A considerable enhancement of photoluminescence (PL) and a notable red shift in the emission maximum of 1 (λ(max) 600 nm) relative to 2 (λ(max) 545 nm) are observed. Electrogenerated chemiluminescence (ECL) of 1 and 2 in the absence or presence of coreactant tri-n-propylamine (TPrA) or 2-(dibutylamino)ethanol (DBAE) at different working electrodes in different solvents (CH(2)Cl(2), CH(2)ClCH(2)Cl, or CH(3)CN) has been studied. The ECL spectra are identical with the PL spectra, indicating that ECL emissions are also due to a MLM'CT [Pt(d)/π (C≡CC(6)H(4)R-4) → Pt(p(z))/Ag(sp)/π* (C≡CC(6)H(4)R-4)] state modified by Pt···Ag and Ag···Ag contacts. ECL of 1- and 2/amine systems in CH(2)ClCH(2)Cl was produced at the potentials of 1.14-1.19 V vs SCE, notably negatively shifted by about 0.38 V compared to those of the Ru(bpy)(3)(2+)/amine system. In all cases, ECL quantum efficiencies of 2 are higher than those of 1 and on the same order of magnitude as that of the [Ru(bpy)(3)](PF(6))(2)/amine system. It is noted that Sudan I tends to decrease the ECL intensity of the 1/DBAE system in CH(2)ClCH(2)Cl at a platinum working electrode. A new ECL method for the determination of Sudan I was developed with a linear range of 2.5 × 10(-5)-1.0 × 10(-3) M and a detection limit of 8.0 × 10(-6) M based on 3 times the ratio of signal-to-noise.

7.
Chem Commun (Camb) ; 57(77): 9890-9893, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34494033

RESUMO

Two newly synthesized ultra-small copper nanoclusters, [Cu3(µ3-H)(µ2-dppy)4](ClO4)2 (1) and [Cu4(µ4-H)(µ2-dppy)4(µ2-Cl)2](ClO4) (2) (dppy = diphenyl-2-pyridylphosphine), have been shown to exhibit ultrabright yellow and yellow-green room-temperature phosphorescence (RTP) emission, with high quantum yields of 71.8% and 63.5%, respectively. Therefore, nanocluster 1 has been applied for the first time as a single component phosphor for yellow and white light-emitting diodes (LEDs) with favourable characteristics.

8.
Nanomaterials (Basel) ; 10(12)2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33334081

RESUMO

The paper describes a new kind of ionogel with both good mechanical strength and high conductivity synthesized by confining the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethane sulfonyl)imide ([Bmim][NTf2]) within an organic-inorganic hybrid host. The organic-inorganic host network was synthesized by the reaction of methyltrimethoxysilane (MTMS), tetraethoxysilane (TEOS), and methyl methacrylate (MMA) in the presence of a coupling agent, offering the good mechanical strength and rapid shape recovery of the final products. The silane coupling agent 3-methacryloxypropyltrimethoxysilane (KH-570) plays an important role in improving the mechanical strength of the inorganic-organic hybrid, because it covalently connected the organic component MMA and the inorganic component SiO2. Both the thermal stability and mechanical strength of the ionogel significantly increased by the addition of IL. The immobilization of [Bmim][NTf2] within the ionogel provided the final ionogel with an ionic conductivity as high as ca. 0.04 S cm-1 at 50 °C. Moreover, the hybrid ionogel can be modified with organosilica-modified carbon dots within the network to yield a transparent and flexible ionogel with strong excitation-dependent emission between 400 and 800 nm. The approach is, therefore, a blueprint for the construction of next-generation multifunctional ionogels.

9.
Nanoscale ; 12(14): 7797-7803, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32219264

RESUMO

The search for active, stable and cost-efficient carbocatalysts for selective oxidation and reduction reactions could make a substantial impact on the catalytic technologies that do not rely on conventional metal based catalysts. Here we report a facile strategy for the synthesis of boron (B) and nitrogen (N) co-doped carbon nanosheets (BNC) by using biomolecule guanine as a carbon (C) and N source and boric acid as the B precursor. The whole synthesis process which leads to the formation of a two dimensional (2D) structure and mesoporosity with high surface areas is simple, metal-free and template-free. The as-synthesized carbon nanosheets possess a series of merits, such as relatively high specific surface area, satisfactory pore structure, enough structural defects, abundant B and N dopants as well as oxygen functional groups. The catalytic assessments demonstrate that the presented carbon catalyst is highly active and selective for the liquid phase oxidation of ethyl lactate to ethyl pyruvate and the reduction of nitrobenzene to aniline and outperforms other equivalent benchmarks. Control experiments confirm the importance of the B and N co-doping as well as the carbon matrix which benefit the electron transfer. The carbonyl group masking test indicates that carbonyl groups play an important role in both the selective oxidation and reductions. Given the diversity in the structure of the nucleobase moiety, they represent ideal building blocks for the catalyst-free and metal-free formation of 2D carbon architectures, only induced by hydrogen bonds. This B and N co-doped synthesis strategy provides guidance for the design of carbon-based catalysts for selective oxidation and reductions.

10.
Dalton Trans ; 49(24): 8347-8353, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32519685

RESUMO

A series of dinuclear platinum(ii) alkynyl complexes [Pt2L2(C[triple bond, length as m-dash]CC6H4R-4)4] (R = H 1, CH32, But3) and unusual tetranuclear Pt(ii)-Ag(i) clusters [Pt2Ag2L(C[triple bond, length as m-dash]CC6H4R-4)6] (R = H, 4; CH3, 5; But, 6), together with novel polymer crystals [Pt2Ag2L(C[triple bond, length as m-dash]CC6H5)6]∞ ([4]∞), were synthesized by a self-assembly reaction between [NBu4]2[Pt(C[triple bond, length as m-dash]CC6H4-R-4)4] and [Ag6L6]6+ (L = 4-(3,5-(diphenylphosphine)phenyl)pyridine). These complexes were characterized by using a range of spectroscopic techniques and complexes 1, 3, 5, and [4]∞ were analysed by X-ray crystallography. Each platinum atom of the Pt(ii)-Ag(i) clusters shows an unusual asymmetric distorted square planar geometry with three alkynyl groups and one bridging L phosphorus atom. Dinuclear complexes 1-3 demonstrate solid-state weak blue luminescence, while tetranuclear Pt(ii)-Ag(i) clusters 4-6 show intense blue-green or yellow-green emission. Furthermore, the crystalline samples of polymer [4]∞ display bright yellow emission (518 nm) that is significantly red-shifted as compared to monomer crystal 4.

11.
Chem Commun (Camb) ; (15): 1601-3, 2006 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-16582992

RESUMO

Incorporation of diplatinum complex Pt2(micro-dppm)2(bpyC[triple bond]C)4 or Pt2(mu-dppm)2(phenC[triple bond]C)4 with Ln(hfac)3(H2O)2 (Ln = Nd, Eu, Yb) gave a series of Pt2Ln2 and Pt2Ln4 bimetallic arrays, in which the excitation of d(Pt) -->pi*(R-C[triple bond]C) MLCT absorption induces sensitisation of lanthanide luminescence through efficient d --> f energy transfer from Pt(II) alkynyl chromophores.

12.
Dalton Trans ; 44(9): 3941-4, 2015 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-25641344

RESUMO

Two windmill-like Ag3Cu5 alkynyl clusters were synthesized and characterized. They display novel PL and ECL properties, which could be modified by changing the substituent on the alkynyl ligands. According to the study of electrochemical behaviours, ECL behaviours and ECL emission spectra of the Ag3Cu5 clusters, a possible ECL mechanism was proposed.


Assuntos
Cobre/química , Piridinas/química , Prata/química , Eletroquímica , Ligantes , Luminescência , Compostos Organometálicos/química , Processos Fotoquímicos
13.
Chem Commun (Camb) ; (17): 2188-9, 2003 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-13678194

RESUMO

Reactions between the building blocks [Ag2(mu-Ph2PXPPh2)2(MeCN)2]2+ and [Pt(C[triple bond]CC6H4R-p)4]2- (R = H, CH3) afforded strongly luminescent acetylide-linked neutral heterohexanuclear complexes Pt2Ag4(mu-Ph2PNPPh2)4 (C[triple bond]CC6H4R-p)4 (R = H, 1; CH3, 2) for X = NH, but a heterotrinuclear complex cation [PtAg2(mu-PPh2CH2PPh2)2 (C[triple bond]CC6H5)2(CH3CN)2]2+ (3(2+)) for X = CH2.

14.
Dalton Trans ; 43(23): 8861-7, 2014 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-24781919

RESUMO

Two novel luminescent hetero-trinuclear complexes [Pt2Ag(µ-dpppy)2(C≡CC6H4R-4)4](ClO4) (R = H, 1; R = CH3, 2; dpppy = 2,6-bis(diphenylphosphino)pyridine) were synthesized by the self-assembly reaction between [Pt(C[triple bond, length as m-dash]CC6H4R-4)4](2-) and [Ag2(µ-dpppy)3](2+) and characterized by elemental analyses, electrospray ionization mass spectrometry, and (1)H NMR and (31)P{(1)H} NMR spectroscopy and by X-ray crystallography for complex 2. Two Pt2Ag complexes show strong luminescence in the solid state, but exhibit weak emission in CH2Cl2 solution and in acetonitrile-water (1 : 1, v : v) solution at room temperature. To overcome the limitations of low water solubility and weak emission in solutions, a new kind of luminescent Pt2Ag@SiO2 nanoparticles was prepared by incorporating the new Pt2Ag acetylides into monodisperse silica nanoparticles. It is noted that Pt2Ag@SiO2 nanoparticles exhibit strong luminescence in aqueous solution, and cyanide anions tend to decrease their luminescence intensity in NaHCO3-NaOH buffer solution. Based on this, a novel nanosensor for highly sensitive detection of cyanide anions was developed in the range of 0.1-10.0 µM.

15.
Dalton Trans ; 41(36): 11219-25, 2012 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-22878791

RESUMO

A series of dinuclear compounds of [Ru(bpy)(2)(tpphz)Ln(TTA)(3)](PF(6))(2) (tpphz = tetrapyrido[3,2-a:2',3'-c:3'',2''-h:3''',4'''-j]phenazine; Ln = Er(III), Nd(III), Yb(III) and Gd(III); TTA = 2-thenoyltrifluoroacetone) have been prepared by attachment of a [Ln(TTA)(3)] fragment at the vacant diimine site of the luminescent mononuclear complex [Ru(bpy)(2)(tpphz)](PF(6))(2). In the solid state, in CH(2)Cl(2) solution and in Tris-HCl buffer solution of these dinuclear complexes Ru-Ln, sensitized near-infrared (NIR) luminescence is observed from Nd and Yb centres following excitation of the d-block unit, which results from the effective Ru → Ln (Ln = Nd, Yb) energy transfer, but no Er-based NIR luminescence is produced. The (3)MLCT (MLCT = metal to ligand charge transfer) emission is partly quenched in the Ru-Nd complex, slightly increased in the Ru-Yb complex, and is not changed in the Ru-Ercomplex. Interestingly, alpha-fetal protein (AFP) tends to decrease the NIR luminescence intensity of the Ru-Nd complex in Tris-HCl buffer solution. A novel NIR luminescent method for the determination of AFP was developed with a linear range of 0.5-18 ng mL(-1), and a detection limit of 0.2 ng mL(-1) based on 3 times the ratio of the signal-to-noise. Considering the attractive features, such as good selectivity, stability and rapidity, the proposed NIR luminescent method provides promising potential for AFP detection in clinical diagnosis and biomedical applications.


Assuntos
Complexos de Coordenação/síntese química , Elementos da Série dos Lantanídeos/química , Rutênio/química , Espectroscopia de Luz Próxima ao Infravermelho , alfa-Fetoproteínas/análise , Complexos de Coordenação/química , Ligantes
16.
Dalton Trans ; 41(35): 10612-8, 2012 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-22836121

RESUMO

Two water soluble Re(I) tricarbonyl diimine complexes containing cationic 2,2'-bipyridyl ligands [Re(L1)(CO)(3)(AN)](2+) (1) and [Re(L2)(CO)(3)(AN)](3+) (2) (L1 and L2: a cationic 2,2'-bipyridyl ligand, AN: acetonitrile) were synthesized and characterized. Their photophysical, electrochemical and electrochemiluminescent properties were investigated. The crystal structures of the two complexes have also been determined. Electrochemiluminescence (ECL) of the two complexes 1 and 2 have been studied in aqueous buffer solution in the presence of co-reactant tri-n-propylamine (TPrA) or 2-(dibutylamino)ethanol (DBAE) at a Au working electrode. The ECL behavior of the complexes was also studied in the presence of several surfactants such as Triton X-100 and Zonyl FSN. The ECL signals of the rhenium(I) complex were enhanced about 190-fold and 70-fold at a Au electrode in the presence of Triton X-100 for the [Re(L1)(CO)(3)(AN)](2+)/TPrA and [Re(L1)(CO)(3)(AN)](2+)/DBAE systems, respectively.

17.
Dalton Trans ; 40(18): 5078-85, 2011 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-21451882

RESUMO

Three rhenium carbonyl complexes 1-3 were synthesized by reaction of the appropriate bidentate pyrazolyl-pyridyl-based ligand L1, L2 (L1 = 2-[1-{4-(bromomethyl)benzyl}-1H-pyrazol-3-yl]pyridine; L2 = 1,4-bis(3-(2-pyridyl)pyrazol-1-ylmethyl)benzene) with [Re(CO)(5)Cl] in toluene. They were characterized by elemental analyses, ESI-MS, (1)H spectroscopy, and X-ray crystallography for 1 and 2. Compounds 1-3 exhibit bright yellow-green luminescence in the solid state and in solution at 298 K with the lifetimes in the microsecond range. It is noteworthy that the luminescent quantum efficiencies of compounds 1-3 are between 0.040 and 0.051, which are much higher than that of the [Re(bpy)(CO)(3)Cl] complex (= 0.019) (M. M. Richter et al., Anal. Chem., 1996, 68, 4370; J. Van Houten et al., J. Am. Chem. Soc., 1976, 98, 4853). Electrogenerated chemiluminescence (ECL) was observed in solutions of these complexes in the absence or presence of coreactant tri-n-propylamine (TPrA) or 2-(dibutylamino)ethanol (DBAE) by stepping the potential of a Pt disk working electrode. The ECL spectra are identical to the photoluminescence spectra, indicating that the chemical reactions following electrochemical oxidation or reduction form the same (3)MLCT excited states as that generated in the photoluminescence experiments. In most cases, the ECL quantum efficiencies of complexes 1-3 are comparable to that of the [Re(L)(CO)(3)Cl] (L = bpy or phen) system. Oxygen tends to substantially decrease ECL intensities of the three rhenium complexes-TPrA system, which could allow them to be used as oxygen sensors.


Assuntos
Complexos de Coordenação/síntese química , Pirazóis/química , Piridinas/química , Rênio/química , Complexos de Coordenação/química , Cristalografia por Raios X , Técnicas Eletroquímicas , Ligantes , Medições Luminescentes , Conformação Molecular , Teoria Quântica
18.
Dalton Trans ; 40(43): 11636-42, 2011 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-21968913

RESUMO

Mononuclear ruthenium complex 1 and dinuclear complex 2 were synthesized by reaction of the appropriate bidentate pyrazolyl-pyridyl-based ligand L (L = 1,4-bis(3-(2-pyridyl)pyrazol-1-ylmethyl)benzene) with cis-Ru(bipy)(2)Cl(2)·2H(2)O. They were characterized by elemental analyses, ESI-MS, (1)H spectroscopy, and X-ray crystallography for 2. Compounds 1 and 2 both emit strongly in solid states and in solutions at 298 K with the lifetimes in the microsecond range. Electrogenerated chemiluminescence (ECL) of complexes 1 and 2 in the absence or presence of coreactant tri-n-propylamine (TPrA) or 2-(dibutylamino)ethanol (DBAE) at different working electrodes in acetonitrile and phosphate buffer solutions (PBS, pH 7.5) was studied. The ECL spectra are identical to the photoluminescence spectra, indicating that the ECL emissions are due to the metal to ligand charge transfer (MLCT). In all cases, ECL quantum efficiencies of dinuclear complex 2 are higher than those of mononuclear complex 1, and ECL quantum efficiencies of complexes 1 and 2/TPrA system are higher than those of DBAE system. It is noted that diuretic furosemide tends to decrease the ECL intensity of complex 2/TPrA system in PBS (pH 7.5) at GC working electrode. A novel ECL method for the determination of diuretic furosemide was developed with a linear range between 2.0 × 10(-7) mol L(-1) and 1.0 × 10(-6) mol L(-1), and a detection limit of 1.2 × 10(-8) mol L(-1) based on 3 times the ratio of signal-to-noise.


Assuntos
Diuréticos/análise , Técnicas Eletroquímicas/métodos , Furosemida/análise , Substâncias Luminescentes/química , Medições Luminescentes/métodos , Rutênio/química , Butilaminas/química , Diuréticos/química , Etanol/análogos & derivados , Etanol/química , Furosemida/química , Ligantes , Estrutura Molecular , Compostos Organometálicos/química , Propilaminas/química , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Ultravioleta
19.
Inorg Chem ; 45(25): 10371-7, 2006 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-17140247

RESUMO

Heteroheptanuclear ReM6 (M = Cu 2, Ag 3) complexes of 5,5-diethynyl-2,2'-bipyridine were prepared by the reaction of [M2(mu-dppm)2(MeCN)2]2+ (dppm = bis(diphenylphosphino)methane) with the precursor compound Re(Me3SiC[triple bond]CbpyC[triple bond]CSiMe3)(CO)3Cl in the presence of potassium fluoride by fluoride-catalyzed desilylation. When [Cu2(mu-dppm)2(MeCN)2]2+ reacts directly with Me3SiC[triple bond]CbpyC[triple bond]CSiMe3, a binuclear CuI complex [Cu2(mu-dppm)2(SiMe3C[triple bond]CbpyC[triple bond]CSiMe3)2]2+ (4) was isolated. Further addition of [Cu2(mu-dppm)2(MeCN)2]2+ into a THF-MeOH (3:1, v/v) solution of 4 in the presence of potassium fluoride induced isolation of a tetradecanuclear CuI14 complex [Cu14(mu-dppm)14(C[triple bond]CbpyC[triple bond]C)2]10+, which is composed of a binuclear Cu2(mu-dppm)2 and four triangular trinuclear Cu3 units. Both heteroheptanuclear ReIMI6 and tetradecanuclear CuI14 complexes display luminescence in both solid states and dichloromethane solutions at room temperature with emissive lifetimes in the range of microseconds. The dual emissive feature for the ReM6 and CuI14 complexes is ascribed tentatively to originate from both MLCT [d(Re/Cu) -->pi* (bpy)] and LMCT (acetylide --> M3) transitions. .

20.
Inorg Chem ; 43(11): 3484-91, 2004 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-15154812

RESUMO

A series of Ag(I)-Cu(I) heteronuclear alkynyl complexes were prepared by reaction of polymeric (MCCC(6)H(4)R-4)(n)() (M = Cu(I) or Ag(I); R = H, CH(3), OCH(3), NO(2), COCH(3)) with [M'(2)(mu-Ph(2)PXPPh(2))(2)(MeCN)(2)](ClO(4))(2) (M' = Ag(I) or Cu(I); X = NH or CH(2)). Heterohexanuclear complexes [Ag(4)Cu(2)(mu-Ph(2)PNHPPh(2))(4)(CCC(6)H(4)R-4)(4)](ClO(4))(2) (R = H, 1; CH(3), 2) were afforded when X = NH, and heterooctanuclear complexes [Ag(6)Cu(2)(micro-Ph(2)PCH(2)PPh(2))(3)(CCC(6)H(4)R-4)(6)(MeCN)](ClO(4))(2) (R = H, 3; CH(3), 4; OCH(3), 5; NO(2), 6) were isolated when X = CH(2). Self-assembly reaction between (MCCC(6)H(4)COCH(3)-4)(n) and [M'(2)(mu-Ph(2)PCH(2)PPh(2))(2)(MeCN)(2)](ClO(4))(2), however, gave heterohexadecanuclear complex [Ag(6)Cu(2)(micro-Ph(2)PCH(2)PPh(2))(3)(CCC(6)H(4)COCH(3)-4)(6)](2)(ClO(4))(4) (7). The heterohexanuclear complexes 1 and 2 show a bicapped cubic skeleton (Ag(4)Cu(2)C(4)) consisting of four Ag(I) and two Cu(I) atoms and four acetylide C donors. The heterooctanuclear complexes 3-6 exhibit a waterwheel-like structure that can be regarded as two Ag(3)Cu(CCC(6)H(5))(3) components put together by three bridging Ph(2)PCH(2)PPh(2) ligands. The heterohexadecanuclear complex 7 can be viewed as a dimer of heterooctanuclear complex [Ag(6)Cu(2)(micro-Ph(2)PCH(2)PPh(2))(3)(CCC(6)H(4)COCH(3)-4)(6)](ClO(4))(2) through the silver and acetyl oxygen (Ag-O = 2.534 (4) A) linkage between two waterwheel-like Ag(6)Cu(2) units. All of the complexes show intense luminescence in the solid states and in fluid solutions. The microsecond scale of lifetimes in the solid state at 298 K reveals that the emission is phosphorescent in nature. The emissive state in compounds 1-5 is likely derived from a (3)LMCT (CCC(6)H(4)R-4 --> Ag(4)Cu(2) or Ag(6)Cu(2)) transition, mixed with a metal cluster-centered (d --> s) excited state. The lowest lying excited state in compounds 6 and 7 containing electron-deficient 4-nitrophenylacetylide and 4-acetylphenylacetylide, respectively, however, is likely dominated by an intraligand (3)[pi --> pi] character.

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