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61.
Two new bichromophoric ruthenium(II) complexes, [Ru(bpy)(2)(bpy-CM)](PF(6))(2) and [Ru(bpy)(2)(bpy-CM343)](PF(6))(2) (bpy=2,2'-bipyridine, CM=coumarin) with appended coumarin ligands have been designed and synthesized. The energy-transfer-based sensing of esterase by the complexes has been studied by using UV/Vis and luminescence spectroscopic methods. The cytotoxicity and the cellular uptake of one of the complexes have also been investigated. 相似文献
62.
Leung SY Tam AY Tao CH Chow HS Yam VW 《Journal of the American Chemical Society》2012,134(2):1047-1056
Dinuclear alkynylplatinum(II) terpyridyl complexes with oligomeric bridge consisting of five repeating meta-phenylene ethynylene (mPE) units have been found to exhibit a strong tendency to fold back onto themselves to form short helical strands through the stabilization of Pt···Pt and π-π interactions. The steric bulk of the terpyridine ligands and the length of the oligomeric bridge have been found to affect the extent of the intramolecular Pt···Pt interaction that governs the stabilization of the short helical strand in solution. Their folding properties via Pt···Pt and π-π stacking interactions have been studied by (1)H NMR, 2D ROESY NMR, electronic absorption, and emission spectroscopies. 相似文献
63.
Bhargava S Kitadai K Masashi T Drumm DW Russo SP Yam VW Lee TK Wagler J Mirzadeh N 《Dalton transactions (Cambridge, England : 2003)》2012,41(16):4789-4798
A mixture of cyclic gold(I) complexes [Au(2)(μ-cis-dppen)(2)]X(2) (X = OTf 1, PF(6)3) and [Au(cis-dppen)(2)]X (X = OTf 2, PF(6)4) is obtained from the reaction of [Au(tht)(2)]X (tht = tetrahydrothiophene) with one equivalent of cis-dppen [dppen = 1,2-bis(diphenylphosphino)ethylene]. The analogous reaction with trans-dppen or dppa [dppa = bis(diphenylphosphino)acetylene] affords the cyclic trinuclear [Au(3)(μ-trans-dppen)(3)]X(3) (X = OTf 11, PF(6)12) and tetranuclear [Au(4)(μ-dppa)(4)]X(4) (X = OTf 13, PF(6)14, ClO(4)15) gold complexes, respectively. Recrystallization of 15 from CH(2)Cl(2)/MeOH yielded a crystal of the octanuclear gold cluster [Au(8)Cl(2)(μ-dppa)(4)](ClO(4))(2)16. Attempts to prepare dicationic binuclear gold(II) species from the reaction of a mixture of 3 and 4 with halogens gave a mixture of products, the components of which confirmed to be acyclic binuclear gold(I) [Au(2)X(2)(cis-dppen)] (X = I 5, Br 7) and cyclic mononuclear gold(III) [AuX(2)(cis-dppen)]PF(6) (X = I 6, Br 8) complexes. Complexes 11-14 reveal weak emission in butyronitrile glass at 77 K, but they are non-emissive at room temperature. Ab initio modelling was performed to determine the charge state of the gold atoms involved. Extensive structural comparisons were made to experimental data to benchmark these calculations and rationalize the conformations. 相似文献
64.
65.
Laryngeal Myasthenia Gravis: Report of 40 Cases 总被引:4,自引:0,他引:4
Vivian H. Mao Mona Abaza Joseph R. Spiegel Steven Mandel Mary Hawkshaw Reinhardt J. Heuer Robert T. Sataloff 《Journal of voice》2001,15(1):122-130
Myasthenia gravis, an autoimmune disorder of the neuromuscular junction, is usually recognized because of ocular complaints or generalized weakness. We report a series of 40 patients who presented with dysphonia as their initial and primary complaint. Diagnostic testing included strobovideolaryngoscopy, electromyography (EMG) with repetitive stimulation and Tensilon testing, and laboratory and radiographic evaluation. Strobovideolaryngoscopy most commonly revealed fluctuating impairment of vocal fold mobility, either unilateral or bilateral. EMG detected evidence of neuromuscular junction abnormalities in all patients. Only one patient had evidence of antiacetylcholine receptor (ACh-R) antibodies, but many other abnormalities suggestive of autoimmune dysfunction were present. Pyridostigmine therapy was initiated in 34 patients but was not tolerated in 4. Of the remaining 30 patients, 23 reported improvement of symptoms. We conclude that myasthenia gravis can present with symptoms confined primarily to the larynx and should be included in the differential diagnosis of dysphonia. 相似文献
66.
Pua Aileen Goh Rui Min Vivian Ee Kim-Huey Huang Yunle Liu Shao Quan Lassabliere Benjamin Yu Bin 《Chromatographia》2021,84(5):507-515
Chromatographia - The separation of isomers is one of the key issues in analysing complex natural matrices, thus commanding a higher separating power from the applied analytical system. In this... 相似文献
67.
Kenneth B. Wood Vivian T. Stannett Pierre Sigwalt 《Journal of polymer science. Part A, Polymer chemistry》1995,33(17):2909-2916
The influence of reaction medium polarity on the ionizing radiation-initiated copolymer-ization of styrene derivatives involving unpaired carbocations is examined. In the copo-lymerization of nonpolar monomers such as p-CH3styrene/styrene, a small effect consistent with that predicted by Laidler-Eyring theory is found. In the copolymerization of nonpolar/polar monomer pairs such as p-CH3styrene/p-Clstyrene and styrene/p-Clstyrene, any such effect is masked by specific solvation phenomena. A competition between such phenomena appears to exist, in which the different cations are dominated by different interactions. The p-Clstyryl cation appears to undergo strong intramolecular complexation with the penultimate aromatic ring in nonpolar conditions; thus, this cation displays increased se-lectivity toward monomers best able to disrupt the complex. The p-CH3styryl and styryl cations do not appear to be subject to such strong complexation; thus, in nonpolar solvent, their selectivity tends towards monomers with the highest cation-solvating ability. The differing copolymerization behavior of the p-Clstyryl cation is consistent with the findings of previous investigations of the effect of reaction medium on chain transfer with these monomers. © 1995 John Wiley & Sons, Inc. 相似文献
68.
69.
Luminescence Behavior of Polynuclear Alkynylcopper(I) Phosphines 总被引:1,自引:0,他引:1
A series of soluble trinuclear and tetranuclear copper(I) complexes containing 3-l acetylides
, and
have been synthesized and shown to exhibit rich photoluminescent behavior at room temperature. The electrochemistry of the trinuclear Cu(I) acetylide complexes and the excited-state redox properties of
have been investigated. The X-ray crystal structures of
and
have been determined. 相似文献
70.
Vivian Wing-Wah Yam 《Journal of organometallic chemistry》2004,689(8):1393-1401
This review describes the design and synthesis of a number of luminescent transition metal alkynyls by this laboratory. The luminescence properties of the complexes have been studied and their emission origin elucidated. Some of these complexes have been shown to be ideal building blocks for the design and construction of luminescent molecular rods and materials, in which the luminescence properties can be readily tuned by changing the alkynyl ligands. Some of them also exhibited luminescence switching behaviour with the “ON-OFF” luminescence states modulated by redox processes, metal ion-binding or solvent composition. 相似文献