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1.
Molecules ; 28(5)2023 Feb 21.
Article in English | MEDLINE | ID: mdl-36903282

ABSTRACT

Polybrominated diphenyl ethers (PBDEs) are classic and emerging pollutants that are potentially harmful to the human immune system. Research on their immunotoxicity and mechanisms suggests that they play an important role in the resulting pernicious effects of PBDEs. 2,2',4,4'-Tetrabrominated biphenyl ether (BDE-47) is the most biotoxic PBDE congener, and, in this study, we evaluated its toxicity toward RAW264.7 cells of mouse macrophages. The results show that exposure to BDE-47 led to a significant decrease in cell viability and a prominent increase in apoptosis. A decrease in mitochondrial membrane potential (MMP) and an increase in cytochrome C release and caspase cascade activation thus demonstrate that cell apoptosis induced by BDE-47 occurs via the mitochondrial pathway. In addition, BDE-47 inhibits phagocytosis in RAW264.7 cells, changes the related immune factor index, and causes immune function damage. Furthermore, we discovered a significant increase in the level of cellular reactive oxygen species (ROS), and the regulation of genes linked to oxidative stress was also demonstrated using transcriptome sequencing. The degree of apoptosis and immune function impairment caused by BDE-47 could be reversed after treatment with the antioxidant NAC and, conversely, exacerbated by treatment with the ROS-inducer BSO. These findings indicate that oxidative damage caused by BDE-47 is a critical event that leads to mitochondrial apoptosis in RAW264.7 macrophages, ultimately resulting in the suppression of immune function.


Subject(s)
Halogenated Diphenyl Ethers , Mitochondria , Mice , Animals , Humans , Reactive Oxygen Species/metabolism , Halogenated Diphenyl Ethers/pharmacology , Mitochondria/metabolism , Macrophages/metabolism
2.
Inorg Chem ; 61(23): 8685-8693, 2022 Jun 13.
Article in English | MEDLINE | ID: mdl-35639458

ABSTRACT

Titanium oxo clusters (TOCs) with accurate molecular structures have potential applications in photocatalysis, such as photocatalytic degradation, hydrogen production, and water oxidation. The hydrolytic stability and light absorption ability of TOCs have important impacts on photocatalysis, where the selection of peripheral organic ligands plays a significant role. In this regard, salicylhydroxamic acid (abbreviated as H3L) attracts our attention, acting as a ligand for its multidentate and dye-functional features, which can increase the hydrolytic stability and broaden light absorption for TOCs. Herein, two TOCs were solvothermally synthesized and structurally characterized using H3L, formulated as [Ti8(µ2-O)2(µ3-O)2(OiPr)12(L)4]·2CH3CN (1) and [Ti16(µ2-O)10(µ3-O)4(PhCOO)14(L)6(HL)2]·4CH3CN·2iPrOH (2). Complex 2 was obtained by adding excessive benzoic acid over the reaction system of 1, resulting in enhanced hydrolytic stability via the replacement of all alkoxy ligands by multidentate ligands for protection. Interestingly, for the first time, the "three-in-one" structural building mode with {Ti6} + {Ti4} + {Ti6} by the common subunits in 2 was observed among all reported TOCs. Moreover, complex 2 can strongly absorb visible light reaching up to 700 nm and exhibit obvious activity for the photodegradation of methyl orange.


Subject(s)
Benzoates , Titanium , Ligands , Salicylamides , Titanium/chemistry
3.
Chem Sci ; 8(11): 7751-7757, 2017 Nov 01.
Article in English | MEDLINE | ID: mdl-30210760

ABSTRACT

Nonlinear optical (NLO) switchable materials are important for photonic and optoelectronic technologies. One important issue for NLO photoswitching, the most studied physical switching approach, is how to improve the switching contrast of second harmonic generation (SHG) in crystals, because the known values are generally below 3 times. Thermoswitching, as another approach, has shown impressive high SHG-switching contrasts (4-∞ times), but the fast decay of thermally induced states demands constant heat sources to maintain specific SHG intensities. We have synthesized a photochromic and thermochromic bistable acentric compound, ß-[(MQ)ZnCl3] (MQ+ = N-methyl-4,4'-bipyridinium), which represents the first crystalline compound with both photo- and heat-induced SHG-switching behavior and the first example of a thermoswitchable NLO crystal that can maintain its expected second-order NLO intensity without any heat source. The SHG-switching contrast can reach about 8 times after laser irradiation or 2 times after thermal annealing. The former value is the highest recorded for photoswitchable NLO crystals. This work also indicates that higher SHG-switching contrasts may be obtained through increasing electron-transfer efficiency, variation of permanent dipole moment, and self-absorption.

4.
Chempluschem ; 81(8): 798-803, 2016 Aug.
Article in English | MEDLINE | ID: mdl-31968827

ABSTRACT

A new series of isostructural lanthanide-based metal-organic frameworks, [H3 O][HN(CH3 )3 ]2 [Ln3 L6 ] (Ln=Gd (1), Eu (2), and Tb (3); H2 L=1,3-benzenedicarboxylic acid), was prepared under solvothermal conditions. Single-crystal XRD studies reveal that these compounds are 3D microporous frameworks with 1D channels distributed in four different directions. The 1D channels contain protonated water molecules and trimethylammonium cations, which can be partially exchanged with different metal ions. Notably, these compounds do not contain any coordinated solvent molecules because the coordination sphere of the Ln3+ ion is fully occupied by chelating and bridging carboxylate oxygen atoms. Tunable colors and white-light emission can be achieved by encapsulating different molar ratios of Eu3+ and Tb3+ ions in the Gd framework through cation exchange. In addition, the Eu framework can act as a sensitive and selective luminescence sensor for both Fe2+ and Fe3+ .

5.
Chem Commun (Camb) ; 49(7): 710-2, 2013 Jan 25.
Article in English | MEDLINE | ID: mdl-23232417

ABSTRACT

A dinuclear ruthenium catalyst with a rigid anthracene spacer shows excellent regio- and stereo-selectivity in the atom-economic addition of aliphatic carboxylic acids to phenylacetylene, producing exclusively anti-Markovnikov enol-esters with high E/Z ratios of the isomers.

6.
Inorg Chem ; 51(12): 6468-75, 2012 Jun 18.
Article in English | MEDLINE | ID: mdl-22670864

ABSTRACT

Ruthenium(II) terpyridine complexes containing the pyrrole-tagged 2,2'-dipyridylamine ligand PPP (where PPP stands for N-(3-bis(2-pyridyl)aminopropyl)pyrrole with the general formula [Ru(tpy)(PPP)X](n+) (1, X = Cl(-); 2, X = H(2)O; 3, X = CH(3)CN; tpy = 2,2':6',2"-terpyridine) have been synthesized and characterized by (1)H NMR, IR, UV-vis, mass spectrometry, and elemental analysis. 1 and 2 have been structurally characterized by X-ray crystallography. Both 1 and 2 were successfully immobilized onto glassy carbon electrode via anodic oxidation of the pyrrole moiety on the PPP ligand to give stable and highly electroactive polymer films. Cyclic voltammetric studies of 1 in acetonitrile revealed a Ru(III)/Ru(II) couple at 0.4 V vs Cp(2)Fe(+/0) initially, but another redox couple resulting from chloride substitution by acetonitrile developed at E(1/2) = 0.82 V upon repetitive potential scan. This ligand substitution was induced by the acidic local environment caused by the release of protons during pyrrole polymerization. The electropolymerization of 2 in aqueous medium allowed the observation of the formation of Ru(IV)═O species in polypyrrole film. As the film grew thicker, the size of the Ru(III)/(/)Ru(II) couple (E(1/2) = 0.8 V vs SCE at pH 1) of poly[Ru(tpy)(PPP)(OH(2))](n+) increased accordingly, whereas the growth of the Ru(IV)/Ru(III) couple (E(1/2) = 0.89 V vs SCE at pH 1) leveled off after the film had reached a certain thickness. The Pourbaix diagram of the E(1/2) of the Ru(III) /Ru(II) and Ru(IV)/Ru(III) couples vs pH of the electrolyte medium has been obtained. The resulting poly[Ru(tpy)(PPP)(OH(2))](n+) film is electrocatalytically active toward the oxidation of benzyl alcohol.


Subject(s)
2,2'-Dipyridyl/analogs & derivatives , Organometallic Compounds/chemistry , Organometallic Compounds/chemical synthesis , Pyridines/chemistry , Pyrroles/chemistry , Ruthenium/chemistry , 2,2'-Dipyridyl/chemistry , Crystallography, X-Ray , Electrochemistry , Ligands , Models, Molecular , Molecular Structure
7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 41(1): 118-20, 2010 Jan.
Article in Chinese | MEDLINE | ID: mdl-20369484

ABSTRACT

OBJECTIVE: To study the roles of uPA and TGF-beta1 in the etiology of preeclampsia (PE). METHODS: The plasma uPA and TGF-beta 1 were determined with enzyme linked immunosorbent assay (ELISA) in 70 patients with PE, and compared with those with normal pregnancy (n = 40). RESULTS: 1) The patients with PE had lower levels of plasma uPA (436.39 +/- 29.57) pg/mL than those with normal pregnancy [(646.54 +/- 35.39) pg/mL, P < 0.01]. No significant difference was found in the levels of plasma uPA between the patients with severe PE (417.11 +/- 48.47) pg/mL and the patients with mild PE [(468.81 +/- 14.91) pg/mL, P > 0.05]. 2) The patients with PE had higher levels of plasma TGF-beta1 (14.32 +/- 4.37) ng/mL than those with normal pregnancy [(9.85 +/- 3.19) ng/mL, P < 0. 05]. No significant difference was found in the levels of plasma TGF-beta1 between the patients with severe PE (15.37 +/- 4.93) ng/mL and the patients with mild PE [(11.21 +/- 2.32) ng/mL, P > 0.05)]. 3) There was a negative correlation between plasma uPA and plasma TGF-beta1 in the patients with PE (r = -0.497, P < 0.01). CONCLUSION: The changes of uPA and TGF-beta1 are associated with the occurrence and development of PE.


Subject(s)
Pre-Eclampsia/blood , Transforming Growth Factor beta1/blood , Urokinase-Type Plasminogen Activator/blood , Adult , Female , Humans , Pre-Eclampsia/etiology , Pregnancy
9.
Zhongguo Zhen Jiu ; 28(9): 673-4, 2008 Sep.
Article in Chinese | MEDLINE | ID: mdl-18822985

ABSTRACT

OBJECTIVE: To compare therapeutic effects of acupuncture on complicated facial paralysis in the patient with HIV/AIDS and in the patient with no HIV/AIDS. METHODS: The observation group of 31 cases of facial paralysis with positive HIV/AIDS and the control group of 30 cases of facial paralysis with negative HIV/AIDS were treated with acupuncture at Yifeng (TE 17), Xiaguan (ST 7), Jiache (ST 6), Taiyang (EX-HN 5), Dicang (ST 4), Yuyao (EX-HN 4), Cuanzhu (BL 2), Yingxiang (LI 20), etc. and with individual treatment according to different periods of disease. The difference of therapeutic effects between the two groups were observed. RESULTS: The effective rate was 83.9% in the observation group and 96.7% in the control group, with no significant difference between the two groups; while the cured rate was 9.7% in the observation group and 73.3% in the control group with a very significant difference between the two groups (P < 0.01). CONCLUSION: Acupuncture with individual treatment has a satisfactory therapeutic effect on complicated facial paralysis in the patient of HIV/AIDS.


Subject(s)
Acquired Immunodeficiency Syndrome/complications , Acupuncture Therapy , Facial Paralysis/therapy , Adolescent , Adult , Female , Humans , Male , Medicine, Chinese Traditional
12.
Chemistry ; 13(30): 8610-9, 2007.
Article in English | MEDLINE | ID: mdl-17642072

ABSTRACT

The perchlorate salt of the dicationic bipy-ruthenium complex cis-[Ru(6,6'-Cl2bipy)2(H2O)2]2+ effectively catalyzes addition of beta-diketones to secondary alcohols and styrenes to yield the alpha-alkylated beta-diketones. In a catalytic addition reaction of acetylacetone to 1-phenylethanol, the kappa2-acetylacetonate complex [Ru(6,6'-Cl2bipy)2(kappa2-acac)]ClO4 was isolated after the catalysis; this complex is readily synthesized by reacting cis-[Ru(6,6'-Cl2bipy)2(H2O)2](ClO4)2 with acetylacetone. [Ru(6,6'-Cl2bipy)2(kappa2-acac)]ClO4 is unreactive toward 1-phenylethanol in the presence of HClO4; it also fails to catalyze the addition of acetylacetone to 1-phenylethanol. On the basis of these observations, it is proposed and confirmed by independent experiments that the catalytic addition of beta-diketones to the secondary alcohols is in fact catalyzed by the Brønsted acid HClO4, which is generated by the reaction of cis-[Ru(6,6'-Cl2bipy)2(H2O)2](ClO4)2 with the beta-diketone.


Subject(s)
Acids/chemistry , Alcohols/chemistry , Ketones/chemistry , Ruthenium Compounds/chemistry , Styrene/chemistry , Catalysis , Crystallography , Magnetic Resonance Spectroscopy , Models, Molecular , Spectrophotometry, Infrared
13.
Chem Commun (Camb) ; (21): 2175-7, 2007 Jun 07.
Article in English | MEDLINE | ID: mdl-17520127

ABSTRACT

A novel Re(I) complex covalently anchored with a pyrrolidinium moiety was successfully synthesized and used as an efficient and recyclable catalyst in the cycloaddition of CO2 with epoxides under mild reaction conditions to give excellent isolated yield and selectivity of cyclic carbonates in pyrrolidinium ionic liquid.


Subject(s)
Carbon Dioxide/chemistry , Ionic Liquids/chemistry , Organometallic Compounds/chemical synthesis , Pyrrolidines/chemistry , Rhenium/chemistry , Catalysis , Crystallography, X-Ray , Cyclization , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Structure , Organometallic Compounds/chemistry
14.
Angew Chem Int Ed Engl ; 45(35): 5842-6, 2006 Sep 04.
Article in English | MEDLINE | ID: mdl-16881024
15.
Chemistry ; 11(23): 7040-53, 2005 Nov 18.
Article in English | MEDLINE | ID: mdl-16163758

ABSTRACT

beta-Halogenated dioxoruthenium(VI) porphyrin complexes [Ru(VI)(F(28)-tpp)O(2)] [F(28)-tpp=2,3,7,8,12,13, 17,18-octafluoro-5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato(2-)] and [Ru(VI)(beta-Br(8)-tmp)O(2)] [beta-Br(8)-tmp=2,3,7,8,12,13,17,18-octabromo-5,10,15,20- tetrakis(2,4,6-trimethylphenyl)porphyrinato(2-)] were prepared from reactions of [Ru(II)(por)(CO)] [por=porphyrinato(2-)] with m-chloroperoxybenzoic acid in CH(2)Cl(2). Reactions of [Ru(VI)(por)O(2)] with excess PPh(3) in CH(2)Cl(2) gave [Ru(II)(F(20)-tpp)(PPh(3))(2)] [F(20)-tpp=5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato(2-)] and [Ru(II)(F(28)-tpp)(PPh(3))(2)]. The structures of [Ru(II)(por)(CO)(H(2)O)] and [Ru(II)(por)(PPh(3))(2)] (por=F(20)-tpp, F(28)-tpp) were determined by X-ray crystallography, revealing the effect of beta-fluorination of the porphyrin ligand on the coordination of axial ligands to ruthenium atom. The X-ray crystal structure of [Ru(VI)(F(20)-tpp)O(2)] shows a Ru=O bond length of 1.718(3) A. Electrochemical reduction of [Ru(VI)(por)O(2)] (Ru(VI) to Ru(V)) is irreversible or quasi-reversible, with the E(p,c)(Ru(VI/V)) spanning -0.31 to -1.15 V versus Cp(2)Fe(+/0). Kinetic studies were performed for the reactions of various [Ru(VI)(por)O(2)], including [Ru(VI)(F(28)-tpp)O(2)] and [Ru(VI)(beta-Br(8)-tmp)O(2)], with para-substituted styrenes p-X-C(6)H(4)CH=CH(2) (X=H, F, Cl, Me, MeO), cis- and trans-beta-methylstyrene, cyclohexene, norbornene, ethylbenzene, cumene, 9,10-dihydroanthracene, xanthene, and fluorene. The second-order rate constants (k(2)) obtained for the hydrocarbon oxidations by [Ru(VI)(F(28)-tpp)O(2)] are up to 28-fold larger than by [Ru(VI)(F(20)-tpp)O(2)]. Dual-parameter Hammett correlation implies that the styrene oxidation by [Ru(VI)(F(28)-tpp)O(2)] should involve rate-limiting generation of a benzylic radical intermediate, and the spin delocalization effect is more important than the polar effect. The k(2) values for the oxidation of styrene and ethylbenzene by [Ru(VI)(por)O(2)] increase with E(p,c)(Ru(VI/V)), and there is a linear correlation between log k(2) and E(p,c)(Ru(VI/V)). The small slope (approximately 2 V(-1)) of the log k(2) versus E(p,c)(Ru(VI/V)) plot suggests that the extent of charge transfer is small in the rate-determining step of the hydrocarbon oxidations. The rate constants correlate well with the C-H bond dissociation energies, in favor of a hydrogen-atom abstraction mechanism.


Subject(s)
Porphyrins/chemistry , Ruthenium Compounds/chemistry , Crystallography, X-Ray , Hydrogen Bonding , Kinetics , Magnetic Resonance Spectroscopy , Models, Molecular , Oxidation-Reduction , Spectrophotometry, Infrared , Spectrophotometry, Ultraviolet , Thermodynamics
16.
J Inorg Biochem ; 99(8): 1661-9, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16005070

ABSTRACT

The syntheses, characteristics of dinuclear macrocyclic polyamine zinc complexes and their interaction with plasmid DNA are reported. The two cyclen (1,4,7,10-tetraazacyclododecane) moieties are bridged by rigid and flexible linkages. The crystal structures of Zn2C27H43N8O15Cl4 [5c.(ClO4)3.2H2O] and Zn2C30H43N10O13Cl3 [5e.(ClO4)3.H2O] have been determined. The complexes crystallize in the monoclinic space group C2/c and P2(1)/c with the following unit cell parameters: 5c.(ClO4)3.2H2O: a=32.568(4)A, b=14.8593(17)A, c=19.443(2)A, alpha=90.00 degrees , beta=119.435(4) degrees , gamma=90.00 degrees , Dc=1.551 mg/m3, FW=956.71, F(000)=3932; 5e.(ClO4)3.H2O: a=15.807(2)A, b=16.756(2)A, c=16.161(2)A, alpha=90.00 degrees , beta=97.062(4) degrees , gamma=90.00 degrees , Dc=1.546 mg/m3, FW=988.83, F(000)=2032. The distance between the two Zn(II) ions is about 4.0 A. The structures show that two zinc ions can synergistically interact with the substrate DNA. With this novel structural characteristics, the dinuclear macrocyclic polyamine Zn(II) complexes via the synergetic effect between the two zinc ions can catalyze the cleavage of plasmid DNA (pUC18) with unprecedented speed at physiological conditions.


Subject(s)
DNA/metabolism , Plasmids/metabolism , Polyamines/chemical synthesis , Polyamines/metabolism , Zinc Compounds/chemical synthesis , Zinc Compounds/metabolism , Crystallography, X-Ray , Cyclization , Models, Molecular , Molecular Structure , Polyamines/chemistry , Zinc Compounds/chemistry
17.
Inorg Chem ; 44(11): 3780-8, 2005 May 30.
Article in English | MEDLINE | ID: mdl-15907102

ABSTRACT

Reaction of dioxoruthenium(VI) porphyrins [Ru(VI)(Por)O2] with arylimine HN=CPh2 in dichloromethane afforded bis(methyleneamido)ruthenium(IV) porphyrins [Ru(IV)(Por)(N=CPh2)2] for Por = 4-Cl-TPP and TMP; (methyleneamido)hydroxoruthenium(IV) porphyrins [Ru(IV)(Por)(N=CPh2)(OH)] for Por = TPP and TTP; and bis(arylimine)ruthenium(II) porphyrins [Ru(II)(Por)(HN=CPh2)2] for Por = 3,5-Cl2TPP and 3,5-(CF3)2TPP. In dichloromethane solution exposed to air, complex [Ru(II)(3,5-Cl2TPP)(HN=CPh2)2] underwent oxidative deprotonation to form [Ru(IV)(3,5-Cl2TPP)(N=CPh2)2]. The new ruthenium porphyrins were identified by 1H NMR, UV-vis, IR, and mass spectroscopy, along with elemental analysis. X-ray crystal structure determinations of [Ru(IV)(4-Cl-TPP)(N=CPh2)2], [Ru(IV)(TPP)(N=CPh2)(OH)], and [Ru(II)(3,5-(CF3)2TPP)(HN=CPh2)2] revealed the Ru-N(methyleneamido) or Ru-N(arylimine) distances of 1.897(5) A (average), 1.808(4) A, and 2.044(2) A (average), respectively.

18.
Inorg Chem ; 44(11): 3942-54, 2005 May 30.
Article in English | MEDLINE | ID: mdl-15907122

ABSTRACT

The syntheses and reactivities of sterically encumbered trans-dioxoosmium(VI) complexes containing Schiff-base ligands bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexane-diamine (H2tBu-salch) and bis(3,5-dibromosalicylidene)-1,2-cyclohexane-diamine (H2Br-salch) are described. Reactions of [Os(VI)tBu-salch)O2] (1a) and [Os(VI)(Br-salch)O2] (1b) with PPh(3), p-X-arylamines (X = NO2, CN), N2H4 x H2O, Ph2NNH2, SOCl2, CF3CO2H, Br2, and I2 under reducing conditions gave [Os(II)(Br-salch)(OPPh3)2] (2), [Os(IV)(Br-salch)(p-X-C6H4NH)2] (3), [mu-O-{Os(IV)(tBu-salch)(p-NO2C6H4NH)}2] (4), [Os(II)(Br-salch)(N2)(H2O)] (5), [Os(IV)(tBu-salch)(OH)(Cl)] (6), [Os(IV)(tBu-salch)(OH)2] (7), [Os(IV)(tBu-salch)Cl2] (8), [Os(IV)(tBu-salch)(CF3CO2)2] (9), [Os(IV)(tBu-salch)Br2] (10), and [Os(IV)(tBu-salch)I2] (11), respectively. X-ray crystal structure determinations of [Os(IV)(Br-salch)(p-NO2C6H4NH)2] (3a), [Os(IV)(Br-salch)(p-CNC6H4NH)2] (3b), 6, 8, 9, and 11 reveal the Os-N(amido) distances to be 1.965(4)-1.995(1) A for the bis(amido) complexes, Os-Cl distances of 2.333(8)-2.3495(1) A for 6 and 8, Os-O(CF3CO2) distances of 2.025(6)-2.041(6) A for 9, and Os-I distances of 2.6884(6)-2.6970(6) A for 11. Upon UV irradiation, (1S,2S)-(1a) reacted with aryl-substituted alkenes to give the corresponding epoxides in moderate yields, albeit with no enantioselectivity. The (1R,2R)-6 catalyzed cyclopropanation of a series of substituted styrenes exhibited moderate to good enantioselectivity (up to 79% ee) and moderate trans selectivity.

19.
Inorg Chem ; 44(5): 1511-24, 2005 Mar 07.
Article in English | MEDLINE | ID: mdl-15732994

ABSTRACT

Reaction of equimolar amounts of AgCN and PCy3 gave the polymer [(Cy3P)Ag(NCAgCN)]infinity (1), whereas employment of excess PCy3 yielded the discrete compound [(Cy3P)2Ag(NCAgCN)] (2). Reacting bis(dicyclohexylphosphino)methane (dcpm) with AgCN in 1:1 and 1:2 molar ratios gave two crystalline forms, namely [Ag2(mu-dcpm)2][Ag(CN)2]2 x (CH3OH)2 (3a x (CH3OH)2) and [Ag2(mu-dcpm)2][Ag(CN)2]2 (3b), respectively. The similar reaction of CuCN with PCy3 afforded the polymeric compound [{(Cy3P)Cu(CN)}3]infinity (4), whereas treatment of CuCN with dcpm gave [Cu2(mu-dcpm)2(CN)2] (5). Employment of diphosphine ligands with longer -(CH2)n- spacers, such as 1,2-bis(dicyclohexylphosphino)ethane (dcpe, n = 2) and 1,3-bis(diphenylphosphino)propane (dppp, n = 3), in reactions with [Cu(CH3CN)4]PF6 and KCN afforded the macrocylic compounds [{Cu(dcpe)}2(CN)(mu-dcpe)]PF6 (6(PF6)) and [{Cu(dppp)}3(CN)2(mu-dppp)]PF6 (7(PF6)), respectively. The hexanuclear complex [Cu(CN)(PCy3)]6 (8) was obtained by reacting CuCN with PCy3 in the presence of sodium pyridine-2-thiolate. The UV-vis absorption spectrum of 1 in acetonitrile displays a weak shoulder at 245 nm (epsilon = 350 dm3 mol(-1) cm(-1)). For 3a, 3b, and 5, the intense absorption bands at lambdamax = 257-276 nm with epsilon values of (1.73-1.80) x 10(4) dm3 mol(-1) cm(-1) are assigned to [ndsigma --> (n + 1)psigma] transitions. Complexes 3a and 3b emit at lambdamax = 365 nm in CH3CN (quantum yield approximately 6 x10(-3), lifetime approximately 0.2 micros). The solid-state emission of 5 (lambdamax = 470 and 488 nm at 298 and 77 K) is red-shifted in energy from that of 4 (lambdamax = 401 and 405 nm at 298 and 77 K, respectively). In 77 K MeOH/EtOH (1:4) glassy solution, complexes 4-8 display intense emission with lambdamax at 382-416 nm, which is assigned to the [3d --> (4s, 4p)] triplet excited state.

20.
J Am Chem Soc ; 127(13): 4562-3, 2005 Apr 06.
Article in English | MEDLINE | ID: mdl-15796507

ABSTRACT

Treatment of [Cu2(dcpm)2]Y2 (dcpm = bis(dicyclohexylphosphino)methane, Y = ClO4-, BF4-, PF6-, CF3SO3-) with refluxing MeOH in the presence of KOH afforded hydride complexes [Cu3(dcpm)3(mu3-H)]Y2 (1) in about 85% yield. Refluxing [Cu2(dcpm)2](PF6)2 with MeOH in the presence of NH3.H2O and air gave a carboxylate complex [Cu2(dcpm)2(O2CCH2OH)]PF6 (2) in 40% yield. All of the complexes 1 and 2 have been characterized by X-ray crystallography. The Cu3 cores in 1 are almost perfectly shielded by the dcpm ligands. Intense photoluminescence was observed for 1 both in the solid state and in solution.

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