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41.
Walstrom A Pink M Tsvetkov NP Fan H Ingleson M Caulton KG 《Journal of the American Chemical Society》2005,127(48):16780-16781
Exchange of deuterium in d6-benzene with all C-H sites in (PNP)Ru(OTf), where PNP is N(SiMe2CH2PtBu2)2 and OTf is OSO2CF3, is rapid at 22 degrees C. Although intact planar triplet (PNP)Ru(OTf) binds N2 only very weakly, these reagents are observed to react rapidly to give a diamagnetic 1:1 adduct whose structure has one tBu C-H bond cleaved: the carbon binds to Ru but the hydrogen is on the PNP nitrogen, creating a secondary amine ligand bound to RuII. It is suggested that the benzene C-D cleavage and the N2 product of tBu C-H bond heterolysis both derive from a common intermediate, [HN(SiMe2CH2PtBu2)(SiMe2CH2PtBuCMe2CH2)] Ru(OTf); the formation energy and structure of this species are discussed on the basis of DFT results. 相似文献
42.
The reaction of Fe(CO)(CH2 CHCHCH2)2 with (Ph2 PCH2)2 results in formation of a mixture of two isomers of Fe(CO)(CH2 CHCHCH2)-(Ph2 PCH2 CH2 PPh2). NMR studies concerning the structures of these isomers and their dynamic behavior in solution are described. 相似文献
43.
Marchenko AV Vedernikov AN Dye DF Pink M Zaleski JM Caulton KG 《Inorganic chemistry》2002,41(16):4087-4089
The reaction of RuHCl(CO)L(2) (L = P(i)Pr(3)) with NO initially forms a 1:1 adduct, shown by DFT calculations and EPR spectroscopy (including the RuD isotopomer) to contain a bent ( 90 degree angle Ru-N-O = 143.9 degrees ) nitrosyl where the majority of the spin density is on the nitrosyl nitrogen. This radical adduct transforms further to give equimolar RuCl(NO)(CO)L(2) and RuHCl(HNO)(CO)L(2), the latter with hydride trans to the nitroxyl ligand HN=O. This is the first observation of the synthesis of coordinated HNO from NO itself. DFT calculations lead to the proposal that this H-atom transfer is effected by free NO, and the lifetime of RuHCl(HNO)(CO)L(2) is indeed qualitatively dependent on the presence of free NO. 相似文献
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45.
J. Nieman J.H. Teuben J.C. Huffman K.G. Caulton 《Journal of organometallic chemistry》1983,255(2):193-204
Mono-cyclopentadienyl complexes CpVX2(PR3)2 and Cp′VX2 (PR3)2 (Cp = η5- C5H5; Cp′ = η5-C5H4Me; R = Me, Et; X = Cl, Br) have been prepared by reaction of VX3(PR3)2 with CpM (M = Na, T1, SnBun3, 1/2 Mg) or Cp′Na. Attempts to prepare analogous complexes with other phosphine ligands, PPh3, PPh2 Me, PPhMe2, Pcy3, DMPE and DPPE failed. Reduction of CpVCl2(PEt3)2 with zinc or aluminium under CO (1 bar) offers a simple method for the preparation of CpV(CO)3(PEt3). The crystal structure of the trimethylphosphine complex CpVCl2(PMe3)2 is reported. 相似文献
46.
Gagana Karkada G Arun Maiya Praveen Arany Mohandas Rao KG Shalini Adiga Shobha U. Kamath 《Photochemistry and photobiology》2023,99(4):1172-1180
Individuals with diabetic foot ulcers have overlapped the inflammatory, proliferative and remodeling phase, making the tissue vulnerable to delayed healing responses. We aimed to establish the dose–response relationship of photobiomodulation therapy of different doses and matrix metalloproteinases in the healing dynamics of diabetic neuropathic ulcers. Diabetes was induced in 126 Albino Wistar rats, and neuropathy was induced to the hind paw by a sciatic nerve injury method. An excisional wound was created on the neuropathy-induced leg. Photobiomodulation therapy of dosages 4, 6, 8, 10, 12 and 15 J cm−2 and wavelength 655 nm and 808 nm was irradiated. Photobiomodulation therapy of dosages 4, 6 and 8 J cm−2 showed better wound healing properties with optimized levels of matrix metalloproteinases-1 and 8. We observed a strong dose response in the experimental group treated with 6 and 8 J cm−2. The findings from the present study conclude that photobiomodulation therapy of dosages 4, 6 and 8 J cm−2 is suggestive of usefulness in diabetic neuropathic ulcer healing. Markers like matrix metalloproteinases may give a clear direction on response to the therapy. Based on the findings from the present study, we recommend to validate the findings for safety and efficacy in future through human prospective randomized controlled clinical trials. 相似文献
47.
Reaction of a (PNP)Ni radical with NO finishes in the time of mixing to form a 1:1 adduct with a NO stretching frequency of 1654 cm (-1). NMR data of this diamagnetic product indicate C 2 v symmetry, which is contradicted by the X-ray structure, which shows it to be nonplanar at Ni, with a geometry intermediate between planar and tetrahedral; the planar geometry is thus the transition state for fluxionality giving time-averaged C 2 v symmetry. The X-ray structure, together with DFT calculations, reveals that the "half-bent" NiNO unit and the intermediate coordination geometry result from a Ni --> NO charge transfer, which has a nonintegral value, resulting in a continuum between NO (+) (hence Ni (0)) and NO (-) (hence Ni (II)). This is related to the nonaxially symmetric character of the Ni --> NO back-donation caused by the (PNP) environment on Ni. Steric effects of ( t )Bu and even chelate constraints are ruled out as the cause of the unusual electronic and structural features. 相似文献
48.
49.
Gottschalk-Gaudig T Huffman JC Gérard H Eisenstein O Caulton KG 《Inorganic chemistry》2000,39(18):3957-3962
The synthesis of Ru(C2H4)(CO)2(dtbpe) (dtbpe = tBu2PC2H4PtBu2), then green [Ru(CO)2(dtbpe)]n is described. In solution, n = 1, while in the solid state, n = 2; the dimer has two carbonyl bridges. DFTPW91, MP2, and CCSD(T) calculations show that the potential energy surface for bending one carbonyl out of the RuP2C(O) plane is essentially flat. Ru(CO)2(dtbpe) reacts rapidly in benzene solution to oxidatively add the H-E bond of H2, HCl, HCCR (R = H, Ph), [HOEt2]BF4, and HSiEt3. The H-C bond of C6HF5 oxidatively adds at 80 degrees C. CO adds, as does the C=C bond of H2C=CHX (X = H, F, Me). The following do not add: N2, THF, acetone, H3COH, and H2O. 相似文献
50.