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1.
Fergus R. Knight Amy L. Fuller Dr. Michael Bühl Dr. Alexandra M. Z. Slawin Prof. J. Derek Woollins Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(25):7503-7516
Four novel 1,8‐disubstituted naphthalene derivatives 4 – 7 that contain chalcogen atoms occupying the peri positions have been prepared and fully characterised by using X‐ray crystallography, multinuclear NMR spectroscopy, IR spectroscopy and MS. Molecular distortion due to noncovalent substituent interactions was studied as a function of the bulk of the interacting chalcogen atoms and the size and nature of the alkyl group attached to them. X‐ray data for 4 – 7 was compared to the series of known 1,8‐bis(phenylchalcogeno)naphthalenes 1 – 3 , which were themselves prepared from novel synthetic routes. A general increase in the E???E′ distance was observed for molecules containing bulkier atoms at the peri positions. The decreased S???S distance from phenyl‐ 1 and ethyl‐ 4 analogues is ascribed to a weaker chalcogen lone pair–lone pair repulsion acting in the ethyl analogue due to the presence of two equatorial S(naphthyl) ring conformations. Two novel peri‐substituted naphthalene sulfoxides of 1 , Nap(O?SPh)(SPh) 8 and Nap(O?SPh)2 9 , which contain different valence states of sulfur, were prepared and fully characterised by using X‐ray crystallography and multinuclear NMR spectroscopy, IR spectroscopy and MS. Molecular structures were analysed by using naphthalene ring torsions, peri‐atom displacement, splay angle magnitude, S???S interactions, aromatic ring orientations and quasi‐linear O?S???S arrangements. The axial S(naphthyl) rings in 8 and 9 are unfavourable for S???S contacts due to stronger chalcogen lone pair–lone pair repulsion. Although quasi‐linear O?S???S alignments suggest attractive interaction is conceivable, analysis of the B3LYP wavefunctions affords no evidence for direct bonding interactions between the S atoms. 相似文献
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Fergus R. Knight Amy L. Fuller Dr. Michael Bühl Dr. Alexandra M. Z. Slawin Prof. J. Derek Woollins Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(25):7617-7634
Three sterically crowded peri‐substituted naphthalene phosphines, Nap[PPh2][ER] (Nap=naphthalene‐1,8‐diyl; ER=SEt, SPh, SePh) 1–3 , which contain phosphorus and chalcogen functional groups at the peri positions have been prepared. Each phosphine reacts to form a complete series of PV chalcogenides Nap[P(E′)(Ph2)(ER)] (E′=O, S, Se). The novel compounds were fully characterised by using X‐ray crystallography and multinuclear NMR spectroscopy, IR spectroscopy and MS. X‐ray data for 1 , 2 , n O , n S , n Se (n=1–3) are compared. Eleven molecular structures have been analysed by naphthalene ring torsions, peri‐atom displacement, splay angle magnitude, X???E interactions, aromatic ring orientations and quasi‐linear arrangements. An increase in the congestion of the peri region following the introduction of heavy chalcogen atoms is accompanied by a general increase in naphthalene distortion. P???E distances increase for molecules that contain bulkier atoms at the peri positions and also when larger chalcogen atoms are bound to phosphorus. The chalcogenides adopt similar conformations that contain a quasi‐linear E???P? C fragment, except for 3 O , which displays a twist‐axial‐twist conformation resulting in the formation of a linear O???Se? C alignment. Ab initio MO calculations performed on 2 O , 3 O , 3 S and 3 Se reveal Wiberg bond index values of 0.02 to 0.04, which indicates only minor non‐bonded interactions; however, calculations on radical cations of 3 O , 3 S and 3 Se reveal increased values (0.14–0.19). 相似文献
3.
Roxana M. Bîrzoi Dr. Delia Bugnariu Dr. Rafael Guerrero Gimeno Dr. Daniela Lungu Vera Zota Dr. Constantin Daniliuc Dr. Peter G. Jones Prof. Dr. Zoltán Benkõ Dr. László Könczöl László Nyulászi Prof. Dr. Rainer Bartsch Dr. Wolf‐W. du Mont Prof. Dr. Edgar Niecke Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(16):4843-4851
Deprotonation of aminophosphaalkenes (RMe2Si)2C?PN(H)(R′) (R=Me, iPr; R′=tBu, 1‐adamantyl (1‐Ada), 2,4,6‐tBu3C6H2 (Mes*)) followed by reactions of the corresponding Li salts Li[(RMe2Si)2C?P(M)(R′)] with one equivalent of the corresponding P‐chlorophosphaalkenes (RMe2Si)2C?PCl provides bisphosphaalkenes (2,4‐diphospha‐3‐azapentadienes) [(RMe2Si)2C?P]2NR′. The thermally unstable tert‐butyliminobisphosphaalkene [(Me3Si)2C?P]2NtBu ( 4 a ) undergoes isomerisation reactions by Me3Si‐group migration that lead to mixtures of four‐membered heterocyles, but in the presence of an excess amount of (Me3Si)2C?PCl, 4 a furnishes an azatriphosphabicyclohexene C3(SiMe3)5P3NtBu ( 5 ) that gave red single crystals. Compound 5 contains a diphosphirane ring condensed with an azatriphospholene system that exhibits an endocylic P?C double bond and an exocyclic ylidic P(+)? C(?)(SiMe3)2 unit. Using the bulkier iPrMe2Si substituents at three‐coordinated carbon leads to slightly enhanced thermal stability of 2,4‐diphospha‐3‐azapentadienes [(iPrMe2Si)2C?P]2NR′ (R′=tBu: 4 b ; R′=1‐Ada: 8 ). According to a low‐temperature crystal‐structure determination, 8 adopts a non‐planar structure with two distinctly differently oriented P?C sites, but 31P NMR spectra in solution exhibit singlet signals. 31P NMR spectra also reveal that bulky Mes* groups (Mes*=2,4,6‐tBu3C6H2) at the central imino function lead to mixtures of symmetric and unsymmetric rotamers, thus implying hindered rotation around the P? N bonds in persistent compounds [(RMe2Si)2C?P]2NMes* ( 11 a , 11 b ). DFT calculations for the parent molecule [(H3Si)2C?P]2NCH3 suggest that the non‐planar distortion of compound 8 will have steric grounds. 相似文献
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The reaction of organomercury(II) halogenides (RHgHal, Hal = Cl, I) with silver azide furnished the corresponding covalent organomercury(II) azides RHgN3 (R = Me ( 1 ), tBu ( 2 ), Ph ( 3 )). In addition to the characterization by multinuclear NMR spectroscopy, IR and Raman spectroscopy as well as mass spectrometry, the mercury content was determined. A dependance on the solventpolarity for the 14N NMR resonances was observed. Furthermore, X‐ray diffraction studies were performed and the crystal structures for mercury(II) azides 1 – 3 are reported. A comparison of the bond lengths and angles with data from theoretical calculations is given. 相似文献
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Patrick M. Hakey Damian G. Allis Dr. Matthew R. Hudson Wayne Ouellette Dr. Timothy M. Korter Prof. 《Chemphyschem》2009,10(14):2434-2444
The terahertz (THz) spectrum of the pharmaceutical (1R,2S)‐(?)‐ephedrine from 8.0 to 100.0 cm?1 is investigated at liquid‐nitrogen (78.4 K) temperature. The spectrum exhibits several distinct features in this range that are characteristic of the crystal form of the compound. A complete structural analysis and vibrational assignment of the experimental spectrum is performed using solid‐state density functional theory (DFT) and cryogenic single‐crystal X‐ray diffraction. Theoretical modeling of the compound includes an array of density functionals and basis sets with the final assignment of the THz spectrum performed at a PW91/6‐311G(d,p) level of theory, which provides excellent solid‐state simulation agreement with experiment. The solid‐state analysis indicates that the seven experimental spectral features observed at low temperature consist of 13 IR‐active vibrational modes. Of these modes, nine are external crystal vibrations and provide approximately 57 % of the predicted spectral intensity. This study demonstrates that the THz spectra of complex pharmaceuticals may be well reproduced by solid‐state DFT calculations and that inclusion of the crystalline environment is necessary for realistic and accurate simulations. 相似文献
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Lucia Ambrosio M. Carla Aragoni Dr. Massimiliano Arca Dr. Francesco A. Devillanova Prof. Michael B. Hursthouse Prof. Dr. Susanne L. Huth Dr. Francesco Isaia Prof. Vito Lippolis Prof. Dr. Annalisa Mancini Dr. Anna Pintus Dr. 《化学:亚洲杂志》2010,5(6):1395-1406
The tetrabutylammonium (TBA+) salts of square‐planar monoanionic gold complexes of the unsymmetrically substituted Ar,H‐edt2? 1,2‐dithiolene ligands (Ar,H‐edt2?=arylethylene‐1,2‐dithiolato; Ar=phenyl ( 1 ?), 2‐naphthyl ( 2 ?), and 1‐pyrenyl ( 3 ?)) were synthesized and characterized by spectroscopic and electrochemical methods and the corresponding neutral species ( 1 , 2 , and 3 , respectively) were obtained in CH2Cl2 solution at room temperature by diiodine oxidation. The single‐crystal X‐ray diffraction structural data collected for (TBA+)( 2 ?), supported by DFT theoretical calculations, are consistent with the ene‐1,2‐dithiolate form of the ligand and the AuIII oxidation state. All complexes feature intense near‐IR absorptions (at about 1.5 μm) in their neutral states and Vis‐emitting properties in the 400–550 nm range, the energy of which is controlled by the charge of the complex in the case of the 3 ?/ 3 couple. The spectroscopic and electrochemical features of 1 x? and 2 x? (x=0, 1), both in their cis and trans conformations, were investigated by means of DFT and time‐dependent (TD) DFT calculations. 相似文献
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Thomas M. Klapötke Prof. Dr. Burkhard Krumm Dr. Matthias Scherr Dr. F. Xaver Steemann Dr. Klaus Banert Prof. Dr. Young‐Hyuk Joo Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(42):11341-11345
The synthesis and structural properties (from X‐ray diffraction or B3LYP/6‐31G(d) calculations) of three energetic compounds derived from tris(chloromethyl)amine and of tris(chloromethyl)amine itself were investigated and compared to those of compounds with similar structures. The compounds have almost planar NC3 units at their amine center, and the substituents bound to the CH2 groups tend to be reactive towards further substitution. Multiple hyperconjugation was used to explain these observations. 相似文献
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Dr. Shinsuke Nishida Dr. Junya Kawai Miki Moriguchi Tomohiro Ohba Naoki Haneda Dr. Kozo Fukui Prof. Akira Fuyuhiro Prof. Daisuke Shiomi Prof. Kazunobu Sato Prof. Takeji Takui Prof. Kazuhiro Nakasuji Prof. Yasushi Morita 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(36):11904-11915
The tri‐tert‐butylphenalenyl (TBPLY) radical exists as a π dimer in the crystal form with perfect overlapping of the singly occupied molecular orbitals (SOMOs) causing strong antiferromagnetic exchange interactions. 2,5‐Di‐tert‐butyl‐6‐oxophenalenoxyl (6OPO) is a phenalenyl‐based air‐stable neutral π radical with extensive spin delocalization and is a counter analogue of phenalenyl in terms of the topological symmetry of the spin density distribution. X‐ray crystal structure analyses showed that 8‐tert‐butyl‐ and 8‐(p‐XC6H4)‐6OPOs (X=I, Br) also form π dimers in the crystalline state. The π‐dimeric structure of 8‐tert‐butyl‐6OPO is seemingly similar to that of TBPLY even though its SOMO–SOMO overlap is small compared with that of TBPLY. The 8‐(p‐XC6H4) derivatives form slipped stacking π dimers in which the SOMO–SOMO overlaps are greater than in 8‐tert‐butyl‐6OPO, but still smaller than in TBPLY. The solid‐state electronic spectra of the 6OPO derivatives show much weaker intradimer charge‐transfer bands, and SQUID measurements for 8‐(p‐BrC6H4)‐6OPO show a weak antiferromagnetic exchange interaction in the π dimer. These results demonstrate that the control of the spin distribution patterns of the phenalenyl skeleton switches the mode of exchange interaction within the phenalenyl‐based π dimer. The formation of the relevant multicenter–two‐electron bonds is discussed. 相似文献
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Dudekula Sharmila Bijan Mondal Rongala Ramalakshmi Sangita Kundu Dr. Babu Varghese Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):5074-5083
A combined experimental and quantum chemical study of Group 7 borane, trimetallic triply bridged borylene and boride complexes has been undertaken. Treatment of [{Cp*CoCl}2] (Cp*=1,2,3,4,5‐pentamethylcyclopentadienyl) with LiBH4 ? thf at ?78 °C, followed by room‐temperature reaction with three equivalents of [Mn2(CO)10] yielded a manganese hexahydridodiborate compound [{(OC)4Mn}(η6‐B2H6){Mn(CO)3}2(μ‐H)] ( 1 ) and a triply bridged borylene complex [(μ3‐BH)(Cp*Co)2(μ‐CO)(μ‐H)2MnH(CO)3] ( 2 ). In a similar fashion, [Re2(CO)10] generated [(μ3‐BH)(Cp*Co)2(μ‐CO)(μ‐H)2ReH(CO)3] ( 3 ) and [(μ3‐BH)(Cp*Co)2(μ‐CO)2(μ‐H)Co(CO)3] ( 4 ) in modest yields. In contrast, [Ru3(CO)12] under similar reaction conditions yielded a heterometallic semi‐interstitial boride cluster [(Cp*Co)(μ‐H)3Ru3(CO)9B] ( 5 ). The solid‐state X‐ray structure of compound 1 shows a significantly shorter boron–boron bond length. The detailed spectroscopic data of 1 and the unusual structural and bonding features have been described. All the complexes have been characterized by using 1H, 11B, 13C NMR spectroscopy, mass spectrometry, and X‐ray diffraction analysis. The DFT computations were used to shed light on the bonding and electronic structures of these new compounds. The study reveals a dominant B?H?Mn, a weak B?B?Mn interaction, and an enhanced B?B bonding in 1 . 相似文献
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Dr. Yang Zhang Kamran B. Ghiassi Qingming Deng Nataliya A. Samoylova Prof. Marilyn M. Olmstead Prof. Alan L. Balch Dr. Alexey A. Popov 《Angewandte Chemie (International ed. in English)》2015,54(2):495-499
The synthesis and single‐crystal X‐ray structural characterization of the first endohedral metallofullerene to contain a heptagon in the carbon cage are reported. The carbon framework surrounding the planar LaSc2N unit in LaSc2N@Cs(hept)‐C80 consists of one heptagon, 13 pentagons, and 28 hexagons. This cage is related to the most abundant Ih‐C80 isomer by one Stone–Wales‐like, heptagon/pentagon to hexagon/hexagon realignment. DFT computations predict that LaSc2N@Cs(hept)‐C80 is more stable than LaSc2N@D5h‐C80, and suggests that the low yield of the heptagon‐containing endohedral fullerene may be caused by kinetic factors. 相似文献
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Different Complexation Behavior of P‐Functionalized Ferrocene Derivatives Towards SnCl2, SnCl4 and SnPh2Cl2: Auto‐ionization and Redox‐Type Reactions 下载免费PDF全文
Dipl.‐Chem. Matthias Gawron Dr. Christina Dietz Michael Lutter Dr. Andrew Duthie Prof. Dr. Viatcheslav Jouikov Prof. Dr. Klaus Jurkschat 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16609-16622
The novel phosphonyl‐substituted ferrocene derivatives [Fe(η5‐Cp)(η5‐C5H3{P(O)(O‐iPr)2}2‐1,2)] ( Fc1,2 ) and [Fe{η5‐C5H4P(O)(O‐iPr)2}2] ( Fc1,1′ ) react with SnCl2, SnCl4, and SnPh2Cl2, giving the corresponding complexes [(Fc1,2)2SnCl][SnCl3] ( 1 ), [{(Fc1,1′)SnCl2}n] ( 2 ), [(Fc1,1′)SnCl4] ( 3 ), [{(Fc1,1′)SnPh2Cl2}n] ( 4 ), and [(Fc1,2)SnCl4] ( 5 ), respectively. The compounds are characterized by elemental analyses, 1H, 13C, 31P, 119Sn NMR and IR spectroscopy, 31P and 119Sn CP‐MAS NMR spectroscopy, cyclovoltammetry, electrospray ionization mass spectrometry, and single‐crystal as well as powder X‐ray diffraction analyses. The experimental work is accompanied by DFT calculations, which help to shed light on the origin for the different reaction behavior of Fc1,1′ and Fc1,2 towards tin(II) chloride. 相似文献
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Dr. Mitsuaki Suzuki Dr. Naomi Mizorogi Tao Yang Prof. Dr. Filip Uhlik Prof. Dr. Zdenek Slanina Prof. Dr. Xiang Zhao Prof. Dr. Michio Yamada Prof. Dr. Yutaka Maeda Prof. Dr. Tadashi Hasegawa Prof. Dr. Shigeru Nagase Prof. Dr. Xing Lu Prof. Dr. Takeshi Akasaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(50):17125-17130
Although all the pure‐carbon fullerene isomers above C60 reported to date comply with the isolated pentagon rule (IPR), non‐IPR structures, which are expected to have different properties from those of IPR species, are obtainable either by exohedral modification or by endohedral atom doping. This report describes the isolation and characterization of a new endohedral metallofullerene (EMF), La2@C76, which has a non‐IPR fullerene cage. The X‐ray crystallographic result for the La2@C76/[NiII(OEP)] (OEP=octaethylporphyrin) cocrystal unambiguously elucidated the Cs(17 490)‐C76 cage structure, which contains two adjacent pentagon pairs. Surprisingly, multiple metal sites were distinguished from the X‐ray data, which implies dynamic behavior for the two La3+ cations inside the cage. This dynamic behavior was also corroborated by variable‐temperature 139 La NMR spectroscopy. This phenomenon conflicts with the widely accepted idea that the metal cations in non‐IPR EMFs invariably coordinate strongly with the negatively charged fused‐pentagon carbons, thereby providing new insights into modern coordination chemistry. Furthermore, our electrochemical and computational studies reveal that La2@Cs(17 490)‐C76 has a larger HOMO–LUMO gap than other dilanthanum‐EMFs with IPR cage structures, such as La2@D3h(5)‐C78 and La2@Ih(7)‐C80, which implies that IPR is no longer a strict rule for EMFs. 相似文献
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Hongke Wang Hui Lin Prof. Wei Xu Prof. Daoben Zhu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(10):3366-3373
Four novel nonsymmetrical photochromic diarylethene compounds containing dithieno[3,2‐b:2′,3′‐d]thiophene units were designed and synthesized to investigate their photochromic properties. All these molecules adopt a photoactive antiparallel conformation in single crystals, as revealed by X‐ray crystallographic analysis, and exhibit excellent photochromism in solution as well as in the crystalline phase. 相似文献
16.
Dr. Annalisa Mancini Dr. M. Carla Aragoni Dr. Neil Bricklebank Dr. Carlo Castellano Prof. Francesco Demartin Prof. Francesco Isaia Prof. Vito Lippolis Dr. Anna Pintus Dr. Massimiliano Arca 《化学:亚洲杂志》2013,8(3):639-647
The reactions of 4,5,6,7‐tetrathiocino‐[1,2‐b:3,4‐b′]‐1,3,8,10‐tetrasubstituted‐diimidazolyl‐2,9‐dithiones (R2,R′2‐todit; 1 : R=R′=Et; 2 : R=R′=Ph; 3 : R=Et, R′=Ph) with Br2 exclusively afforded 1:1 and 1:2 “T‐shaped” adducts, as established by FT‐Raman spectroscopy and single‐crystal X‐ray diffraction in the case of complex 1? 2 Br2. On the other hand, the reactions of compounds 1 – 3 with molecular I2 provided charge‐transfer (CT) “spoke” adducts, among which the solvated species 3? 2 I2 ? (1?x)I2 ? x CH2Cl2 (x=0.94) and ( 3 )2 ? 7 I2 ? x CH2Cl2, (x=0.66) were structurally characterized. The nature of all of the reaction products was elucidated based on elemental analysis and FT‐Raman spectroscopy and supported by theoretical calculations at the DFT level. 相似文献
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Synthesis,Structure, and Air‐stable N‐type Field‐Effect Transistor Behaviors of Functionalized Octaazanonacene‐8,19‐dione 下载免费PDF全文
Chengyuan Wang Dr. Jing Zhang Dr. Guankui Long Prof. Dr. Naoki Aratani Prof. Dr. Hiroko Yamada Prof. Dr. Yang Zhao Prof. Dr. Qichun Zhang 《Angewandte Chemie (International ed. in English)》2015,54(21):6292-6296
Increasing the length of N‐heteroacenes or their analogues is highly desirable because such materials could have great potential applications in organic electronics. In this report, the large π‐conjugated N‐heteroquinone 6,10,17,21‐tetra‐((triisopropylsilyl)ethynyl)‐5,7,9,11,16,18,20,22‐octaazanonacene‐8,19‐dione (OANQ) has been synthesized and characterized. The as‐prepared OANQ shows high stability under ambient conditions and has a particularly low LUMO level, which leads to it being a promising candidate for air‐stable n‐type field‐effect transistors (FETs). In fact, FET devices based on OANQ single crystals have been fabricated and an electron mobility of up to 0.2 cm2 V?1 s?1 under ambient conditions is reported. More importantly, no obvious degradation was observed even after one month. Theoretical calculations based on the single crystal are consistent with the measured mobility. 相似文献
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Theoretical and Structural Analysis of Long CC Bonds in the Adducts of Polycyanoethylene and Anthracene Derivatives and Their Connection to the Reversibility of Diels–Alder Reactions 下载免费PDF全文
Dr. Anna K. H. Hirsch Dr. Philippe Reutenauer Marc Le Moignan Dr. Sébastien Ulrich Dr. Peter J. Boul Prof. Jack M. Harrowfield Dr. Peter D. Jarowski Prof. Dr. Jean‐Marie Lehn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(4):1073-1080
X‐ray structure determinations on four Diels–Alder adducts derived from the reactions of cyano‐ and ester‐substituted alkenes with anthracene and 9,10‐dimethylanthracene have shown the bonds formed in the adduction to be particularly long. Their lengths range from 1.58 to 1.62 Å, some of the longest known for Diels–Alder adducts. Formation of the four adducts is detectably reversible at ambient temperature and is associated with free energies of reaction ranging from ?2.5 to ?40.6 kJ mol?1. The solution equilibria have been experimentally characterised by NMR spectroscopy. Density‐functional‐theory calculations at the MPW1K/6‐31+G(d,p) level with PCM solvation agree with experiment with average errors of 6 kJ mol?1 in free energies of reaction and structural agreement in adduct bond lengths of 0.013 Å. To understand more fully the cause of the reversibility and its relationship to the long adduct bond lengths, natural‐bond‐orbital (NBO) analysis was applied to quantify donor–acceptor interactions within the molecules. Both electron donation into the σ*‐anti‐bonding orbital of the adduct bond and electron withdrawal from the σ‐bonding orbital are found to be responsible for this bond elongation. 相似文献