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61.
Ab initio CI calculations are presented for potential curves for the valence states of HCl, for the vertical electronic spectrum and for the potential curve for the B 1Σ+ state. The valence 1Π, 3Π and 3Σ+ states are found to be repulsive. Calculated vertical excitation energies are in good agreement with experiment. The B 1Σ+ curve is predicted to have a double minimum. 相似文献
62.
63.
Ryan J. Schwamm Mathew D. Anker Matthias Lein Martyn P. Coles 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(5):1503-1507
The potassium aluminyl complex K[Al(NONAr)] (NON=NONAr=[O(SiMe2NAr)2]2?, Ar=2,6‐iPr2C6H3) reacts with 1,3,5,7‐cyclooctatetraene (COT) to give K[Al(NONAr)(COT)]. The COT‐ligand is present in the asymmetric unit as a planar μ2‐η2:η8‐bridge between Al and K, with additional K???π‐aryl interactions to neighboring molecules that generate a helical chain. DFT calculations indicate significant aromatic character, consistent with reduction to [COT]2?. Addition of 18‐crown‐6 causes a rearrangement of the C8‐carbocycle to form the isomeric 9‐aluminabicyclo[4.2.1]nona‐2,4,7‐triene anion. 相似文献
64.
Dimitra Vernardou Charalampos Drosos Andreas Kafizas Martyn E. Pemble Emmanouel Koudoumas 《Molecules (Basel, Switzerland)》2020,25(23)
The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials. 相似文献
65.
66.
Ryan J. Schwamm Dr. Mathew D. Anker Dr. Matthias Lein Dr. Martyn P. Coles Dr. Christopher M. Fitchett 《Angewandte Chemie (International ed. in English)》2018,57(20):5885-5887
Reduction of the indate complex In(NONAr)(μ‐Cl)2Li(OEt2)2 (NONAr=[O(SiMe2NAr)2]2?; Ar=2,6‐iPr2C6H3) with sodium generates the InII diindane species [In(NONAr)]2. Further reduction with a mixture of potassium and [2.2.2]crypt affords the InI N‐heterocyclic indyl anion [In(NONAr)]?, which crystallizes with a non‐contacted [K([2.2.2]crypt)]+ cation. The indyl anion can also be isolated as the indyllithium compound In(NONAr)(Li{THF}3), which contains an In?Li bond. Density functional theory calculations show that the HOMO of the indyl anion is a metal‐centred lone pair, and preliminary reactivity studies confirm its nucleophilic behaviour. 相似文献
67.
Maulik N. Mungalpara Jingjing Wang Martyn P. Coles Paul G. Plieger Gareth J. Rowlands 《Tetrahedron》2018,74(38):5519-5527
A planar chiral secondary phosphine oxide based on [2.2]paracyclophane was synthesized and its chemistry investigated; it was shown to be a competent pre-ligand in palladium(0)-mediated reactions, and displayed promising activity in gold(I)-catalysed cyclisations. The secondary phosphine oxide could be transformed into a collection of P-stereogenic tertiary phosphine oxides. These are rare examples of the planar chirality of [2.2]paracyclophane being combined with a P-stereogenic centre. Unfortunately, epimerisation of the phosphorus stereocentre during reduction limits the use of this chemistry. 相似文献
68.
A group G has finite rank r if every finitely generated subgroup of G is at most r-generator. If C is a class of groups then we let C* denote the class of groups G in which every proper subgroup of G is either of finite rank or in C. We let denote the class of soluble groups and the class of soluble groups of derived length at most d, where d is a positive integer. We let λ denote the set of closure operations
and let denote the λ-closure of the class of periodic locally graded groups. Amongst other results we prove that a soluble -group is either of finite rank or of derived length at most d and also that a group in the class is either locally soluble, or has finite rank, or is isomorphic to one of or for suitable locally finite fields .
The second author would like to thank the Department of Mathematics at Bucknell University for its hospitality while part
of this work was being done. 相似文献
69.
Khalaf MS Coles MP Hitchcock PB 《Dalton transactions (Cambridge, England : 2003)》2008,(32):4288-4295
Partial deprotonation of the bicyclic guanidine 1,4,6-triazabicyclo[3.3.0]oct-4-ene (Htbo) is achieved using (n)BuLi. Isolation of the resulting lithium salts has resulted in the structural characterization of the mixed anion complex {[Li(tbo)()(tboH)](2)}(infinity) (where -H = 1-(2-aminoethyl)-2-imidazolidinethione) and the partially deprotonated salt Li(6)(tbo)(6)(Htbo)(3), . The neutral guanidine Htbo reacts cleanly with AlMe(3) and ZnMe(2) to afford the organometallic complexes [Al(tbo)Me(2)](2) [](2), and Zn(3)(tbo)(4)Me(2) (). Structural characterization of these compounds enables comparison between the {5:5}-bicyclic system, [tbo](-), and the previously reported {6:6}-bicyclic system, [hpp](-) (where hppH = 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine). Results indicate that delocalization within the [tbo](-) anion is restricted to the CN(2) amidinate component, with retention of electron density in the non-bonding nitrogen lone-pair. These conclusions are supported by a DFT analysis of the neutral guanidines, Htbo and hppH. 相似文献
70.
Jones LF Inglis R Cochrane ME Mason K Collins A Parsons S Perlepes SP Brechin EK 《Dalton transactions (Cambridge, England : 2003)》2008,(44):6205-6210
The synthesis and magnetic properties of three new members of a family of salicyaldoxime based [Mn6] single-molecule magnets possessing new structural types, core topologies and Mn oxidation state distributions are reported. The isostructural complexes [MnIII6O2(R-sao)6(X)2(EtOH)6] (R = Et, X = Br (1); R = Me, X = I (2)) exhibit single-molecule magnet behaviour with spin Hamiltonian parameters S = 12, g = 1.98 and D = -0.36 cm(-1) in both cases. The hexametallic cluster [MnIII4MnIV2O2(OMe)(4-)(Et-sao)6(MeOH)2].MeOH (3.MeOH) possesses a planar rod-like topology and a mixed valent [MnIV4MnIII2] core, which is unprecedented in this family of [Mn6] SMMs. 相似文献