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81.
A series of new coordination polymers bearing the [B(O–C6H4–CN)4]– anion was synthesized. Two new, one dimensional coordination frameworks of the type M[B(O–C6H4–CN)4] (M = Ag, Cu) were obtained by salt metathesis. The reactivity towards organic Lewis‐bases was studied. The reaction with bidentate ligands yielded two dimensional networks with the general formula [M(L)][B(O–C6H4–CN)4] {L = 2,2′‐bipyridine, 4,4′‐bipyridine, 1,2‐bis(pyridyl)ethane, 1,4‐diazabicyclo[2.2.2]octane}. The synthesis, properties and single crystal structure are reported. 相似文献
82.
Pradip Ghosh Roland Schoch Matthias Bauer Axel Jacobi von Wangelin 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2022,134(1):e202110821
Metal-catalyzed C?H activations are environmentally and economically attractive synthetic strategies for the construction of functional molecules as they obviate the need for pre-functionalized substrates and minimize waste generation. Great challenges reside in the control of selectivities, the utilization of unbiased hydrocarbons, and the operation of atom-economical dehydrocoupling mechanisms. An especially mild borylation of benzylic CH bonds was developed with the ligand-free pre-catalyst Co[N(SiMe3)2]2 and the bench-stable and inexpensive borylation reagent B2pin2 that produces H2 as the only by-product. A full set of kinetic, spectroscopic, and preparative mechanistic studies are indicative of a tandem catalysis mechanism of CH-borylation and dehydrocoupling via molecular CoI catalysts. 相似文献
83.
84.
85.
Axel Ruhe 《BIT Numerical Mathematics》2012,52(2):271-272
86.
Axel D. Becke 《Molecular physics》2015,113(13-14):1884-1889
The energy surfaces of the ground and low-lying excited states of ethylene are challenging tests of multi-reference electronic structure methods. A variety of multi-reference wavefunction theories have been applied to this problem and the ensuing photochemistry has been well studied. Density-functional methods, however, have been less successful. In this work, the ‘B13’ strong-correlation density functional is used to generate multi-reference orbitals for the computation of the three lowest-lying singlet states. We explore the states and energies as a function of torsion angle, and as a function of the pyramidalisation angle with respect to the twisted orthogonal structure. The former features an avoided crossing at the orthogonal structure; the latter a Cs slice through a conical intersection. Both features are well reproduced by our B13 method. 相似文献
87.
Christopher Hubrich Axel Schulz Harald Brand Alexander Villinger 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2179-2196
The silyl ethers (siloxanes) Me4? xSi(OC6H5CN)x (x = 1–4) (1–4), O(Si(OC6H4CN) (Me)2)2 (5), and Me3Si–O–C6F4CN (6) have been synthesized by the reaction of the respective p-hydroxybenzonitriles and chlorosilanes in the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) as hydrogen chloride acceptor. All compounds have been fully characterized by CHN-analysis, melting point, IR, Raman, mass spectroscopy, and 1H, 13C, 29Si NMR spectroscopy. Furthermore, the crystal structures of these compounds—with the exception of Me2Si(OC6H5CN)2, which is a liquid—were determined by X-ray diffractometry. 相似文献
88.
Rainer Bartsch Christian Müller Axel Fischer Peter G. Jones 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Syntheses and structures of penta- and hexaphosphorus analogues of ferrocene have been described recently1. Unlike their simple ferrocene analogues, these complexes have further ligating potential towards other transition metal centres by virtue of the availability of the ring phosphorus lone-pair electrons that are not involved in the η5-coordination. We now describe the first examples of coordination compounds of the triphospha-ferrocene [Fe(η5-C5Me5) (η5-C2 tBu2P3]. In the ruthenium complex [Fe(η5-C5Me5)(η5-C2 tBu2P3) Ru3(CO)9] 2 two adjacent phosphorus atoms of the η5-C2 tBu2P3 ring are interlinked by a ruthenium carbonyl cluster in which all three ruthenium atoms interact with the phosphorus atoms. The tetrametallic nickel complex [Fe(η5-C5Me5)(η5-C2 tBu2P3)Ni(CO)2]2 3 represents the first example of intermolecular interlinkage of two phospha-ferrocene systems by two metal centres. 相似文献
89.
Damir A. Safin Maria G. Babashkina Michael Bolte Axel Klein 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):2426-2432
The reaction of O,O′-diisopropylphosphoric acid isothiocyanate (iPrO)2P(O)NCS with 2-methylaniline 2-MeC6H4NH2, 2,6-dimethylaniline 2,6-Me2C6H3NH2, or 2,4,6-trimethylaniline 2,4,6-Me3C6H2NH2 leads to the N-phosphorylated thioureas RNHC(S)NHP(O)(OiPr)2 (R = 2-MeC6H4?, HLI ; 2,6-Me2C6H3?, HLII ; 2,4,6-Me3C6H2?, HLIII ). Reaction of the potassium salts of HLI –III with Ni(II) in aqueous EtOH leads to [Ni(LI–III-N,S)2] ([NiLI–III 2 ]) chelate complexes. The compounds obtained were investigated by 1H, 31P{1H} NMR spectroscopy and microanalysis. The molecular structure of the thiourea HLIII was elucidated by single crystal X-ray diffraction analysis. Single crystal X-ray diffraction studies showed that HLIII forms both intra- and intermolecular hydrogen bonds, which in turn leads to the formation of polymeric chains. One of the intermolecular hydrogen bonds is of the type N?H…S. Moreover, the formation of intermolecular C?H…η6-phenyl interactions was established. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
90.
Valeria van Axel Castelli Antonella Dalla Cort Luigi Mandolini Valentina Pinto David N. Reinhoudt Fabrizio Ribaudo 《Supramolecular chemistry》2013,25(2-3):211-219
The complexation of the salophen-uranyl metallocleft 2 and of its half-cleft analogue 3 with enones and other carbonyl compounds was assessed in chloroform by UV-Vis titration and, occasionally, by FT-IR measurements. Complexes with receptors 2 and 3 are in all cases more stable than those with the control unsubstituted uranyl-salophen 1 , showing that in addition to the primary binding force provided by coordination of the carbonyl oxygen to the uranium, a significant driving force for complexation, typically in the range of 2-3 kcal/mol, results from van der Waals interactions of the guest with the aromatic walls. Replacement of the phenyl group in 3 with larger aromatic residues to give 4 and 5 , led to enhanced complex stabilities, due to more extended contact surfaces between host and guest. 相似文献