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W. Kuchen E. Lehnert Peter Panster Peter Kleinschmit 《Phosphorus, sulfur, and silicon and the related elements》2013,188(3-4)
Abstract On mixing organic solutions of [Et2PS2]M/n and [Prop2PS2]M/n [M=Pd(II), Pt(II), Rh(III), lr(III), Cr(III)] an equilibrium is obtained containing statistical amounts of the corresponding mixed ligand complexes as can be shown by 31P{1H}-NMR, HPLC and FD-MS. With Pt(II)- and Pd(II)-chelates the kinetics of ligand exchange was determined by HPLC. Mixed complexes ML2L′ and MLL′2 were isolated from the equilibrium solutions in case of the more inert Cr(III)-, Rh(III)- and lr(III)-chelates by preparative HPLC. Pd(II), Pt(II) and Rh(III) can be determined quickly and simultaneously in aqueous solutions at nanogramm level by complexation with Et2PS2? in a modified sample loop followed by reversed phase HPLC. 相似文献
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Novel silicon and tin compounds were synthesized by the reaction of lithium salts of 1,3-di-phenyl-1,1,3,3-tetramethyldisilazane
H(DPTMDS) and 1,1,3,3,5,5-hexamethylcyclotrisilazane H3(HMCTS) with SiCl4 and SnCl4, respectively. The reactions with H(DPTMDS) yield the substitution products (DPTMDS)2SiCl2 and (DPTMDS)2SnCl2. In contrast, the reactions with the cyclic silazane H3(HMCTS) lead to a large variety of products due to the competition of substitution reactions and ring contractions. The resulting
new compounds were characterized by elemental analyses, NMR spectroscopy, and single crystal X-ray structure analyses.
Dedicated to Prof. Edmunds Lukevics on the occasion of his 70th birthday
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1845–1856, December, 2006. 相似文献
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We measure the noise added by an atomic point contact operated as a displacement detector. With a microwave technique, we increase the measurement speed of atomic point contacts by a factor of 500. The measurement is then fast enough to detect the resonant motion of a nanomechanical beam at frequencies up to 60 MHz and sensitive enough to observe the random thermal motion of the beam at 250 mK. We demonstrate a shot-noise limited imprecision of 2.3 fm/square root[Hz] and observe a 78 aN/square root[Hz] backaction force, yielding a total uncertainty in the beam's displacement that is 42 times the standard-quantum limit. 相似文献
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N Lehnert R Y Ho L Que E I Solomon 《Journal of the American Chemical Society》2001,123(51):12802-12816
The spectroscopic properties of the high-spin Fe(III)-alkylperoxo model complex [Fe(6-Me(3)TPA)(OH(x))(OO(t)Bu)](x)(+) (1; TPA = tris(2-pyridylmethyl)amine, (t)Bu = tert-butyl, x = 1 or 2) are defined and related to density functional calculations of corresponding models in order to determine the electronic structure and reactivity of this system. The Raman spectra of 1 show four peaks at 876, 842, 637, and 469 cm(-1) that are assigned with the help of normal coordinate analysis, and corresponding force constants have been determined to be 3.55 mdyn/A for the O-O and 2.87 mdyn/A for the Fe-O bond. Complex 1 has a broad absorption feature around 560 nm that is assigned to a charge-transfer (CT) transition from the alkylperoxo to a t(2g) d orbital of Fe(III) with the help of resonance Raman profiles and MCD spectroscopy. An additional contribution to the Fe-O bond arises from a sigma interaction between and an e(g) d orbital of iron. The electronic structure of 1 is compared to the related low-spin model complex [Fe(TPA)(OH(x))(OO(t)Bu)](x)(+) and the reaction coordinate for O-O homolysis is explored for both the low-spin and the high-spin Fe(III)-alkylperoxo systems. Importantly, there is a barrier for homolytic cleavage of the O-O bond on the high-spin potential energy surface that is not present for the low-spin complex, which is therefore nicely set up for O-O homolysis. This is reflected by the electronic structure of the low-spin complex having a strong Fe-O and a weak O-O bond due to a strong Fe-O sigma interaction. In addition, the reaction coordinate of the Fe-O homolysis has been investigated, which is a possible decay pathway for the high-spin system, but which is thermodynamically unfavorable for the low-spin complex. 相似文献
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