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1.
Dr. Shenglai Yao M. Sc. Nils Lindenmaier Dr. Yun Xiong Prof. Dr. Shigeyoshi Inoue Dr. Tibor Szilvási Dipl.‐Chem. Mario Adelhardt Dr. Jörg Sutter Prof. Dr. Karsten Meyer Prof. Dr. Matthias Driess 《Angewandte Chemie (International ed. in English)》2015,54(4):1250-1254
The unusual reactivity of the newly synthesized β‐diketiminato cobalt(I) complexes, [(LDepCo)2] ( 2 a , LDep=CH[C(Me)N(2,6‐Et2C6H3)]2) and [LDippCo ? toluene] ( 2 b , LDipp=CH[CHN(2,6‐iPr2C6H3)]2), toward white phosphorus was investigated, affording the first cobalt(I) complexes [(LDepCo)2(μ2:η4,η4‐P4)] ( 3 a ) and [(LDippCo)2(μ2:η4,η4‐P4)] ( 3 b ) bearing the neutral cyclo‐P4 ligand with a rectangular‐planar structure. The redox chemistry of 3 a and 3 b was studied by cyclic voltammetry and their chemical reduction with one molar equivalent of potassium graphite led to the isolation of [(LDepCo)2(μ2:η4,η4‐P4)][K(dme)4] ( 4 a ) and [(LDippCo)2(μ2:η4,η4‐P4)][K(dme)4] ( 4 b ). Unexpectedly, the monoanionic Co2P4 core in 4 a and 4 b , respectively, contains the two‐electron‐reduced cyclo‐P42? ligand with a square‐planar structure and mixed‐valent cobalt(I,II) sites. The electronic structures of 3 a , 3 b , 4 a , and 4 b were elucidated by NMR and EPR spectroscopy as well as magnetic measurements and are in agreement with results of broken‐symmetry DFT calculations. 相似文献
2.
Maria Haimerl Dr. Christian Graßl Dr. Michael Seidl Dr. Martin Piesch Prof. Dr. Manfred Scheer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(72):18129-18134
The reactivity of white phosphorus and yellow arsenic towards two different nickel nacnac complexes is investigated. The nickel complexes [(L1Ni)2tol] ( 1 , L1=[{N(C6H3iPr2-2,6)C(Me)}2CH]−) and [K2][(L1Ni)2(μ,η1 : 1-N2)] ( 6 ) were reacted with P4, As4 and the interpnictogen compound AsP3, respectively, yielding the homobimetallic complexes [(L1Ni)2(μ-η2,κ1:η2,κ1-E4)] (E=P ( 2 a ), As ( 2 b ), AsP3 ( 2 c )), [(L1Ni)2(μ,η3 : 3-E3)] (E=P ( 3 a ), As ( 3 b )) and [K@18-c-6(thf)2][L1Ni(η1 : 1-E4)] (E=P ( 7 a ), As ( 7 b )), respectively. Heating of 2 a , 2 b or 2 c also leads to the formation of 3 a or 3 b . Furthermore, the reactivity of these compounds towards reduction agents was investigated, leading to [K2][(L1Ni)2(μ,η2 : 2-P4)] ( 4 ) and [K@18-c-6(thf)3][(L1Ni)2(μ,η3 : 3-E3)] (E=P ( 5 a ), As ( 5 b )), respectively. Compound 4 shows an unusual planarization of the initial Ni2P4-prism. All products were comprehensively characterized by crystallographic and spectroscopic methods. 相似文献
3.
Anthony Cavaillé Dr. Nathalie Saffon‐Merceron Dr. Noel Nebra Dr. Marie Fustier‐Boutignon Dr. Nicolas Mézailles 《Angewandte Chemie (International ed. in English)》2018,57(7):1874-1878
Reduction of the FeII complex [(PhPP2Cy)FeCl2] ( 2 ) generated an electron‐rich and unsaturated Fe0 species, which was reacted with white phosphorus. The resulting new complex, [(PhPP2Cy)Fe(η4‐P4)] ( 3 ), is the first iron cyclo‐P4 complex and the only known stable end‐deck cyclo‐P4 complex outside Group V. Complex 3 features an FeII center, as shown by Mössbauer spectroscopy, associated to a P42? fragment. The distinct reactivity of complex 3 was rationalized by analysis of the molecular orbitals. Reaction of complex 3 with H+ afforded the unstable complex [(PhPP2Cy)Fe(η4‐P4)(H)]+ ( 4 ), whereas with CuCl and BCF, the complexes [(PhPP2Cy)Fe(η4:η1‐P4)(μ‐CuCl)]2 ( 5 ) and [(PhPP2Cy)Fe(η4:η1‐P4)B(C6F5)3] ( 6 ) were formed. 相似文献
4.
5.
Martin Piesch Christian Graßl Manfred Scheer 《Angewandte Chemie (International ed. in English)》2020,59(18):7154-7160
The redox chemistry of [(Cp′′′Co)2(μ,η2:η2‐E2)2] (E=P ( 1 ), As ( 2 ); Cp′′′=1,2,4‐tri(tert‐butyl)cyclopentadienyl) was investigated. Both compounds can be oxidized and reduced twice. That way, the monocations [(Cp′′′Co)2(μ,η4:η4‐E4)][X] (E=P, X=BF4 ( 3 a ), [FAl] ( 3 b ); E=As, X=BF4 ( 4 a ), [FAl] ( 4 b )), the dications [(Cp′′′Co)2(μ,η4:η4‐E4)][TEF]2 (E=P ( 5 ), As ( 6 )), and the monoanions [K(18‐c‐6)(dme)2][(Cp′′′Co)2(μ,η4:η4‐E4)] (E=P ( 7 ), As ( 8 )) were isolated. Further reduction of 7 leads to the dianionic complex [K(18‐c‐6)(dme)2][K(18‐c‐6)][(Cp′′′Co)2(μ,η3:η3‐P4)] ( 9 ), in which the cyclo‐P4 ligand has rearranged to a chain‐like P4 ligand. Further reduction of 8 can be achieved with an excess of potassium under the formation of [K(dme)4][(Cp′′′Co)2(μ,η3:η3‐As3)] ( 10 ) and the elimination of an As1 unit. Compound 10 represents the first example of an allylic As3 ligand incorporated into a triple‐decker complex. 相似文献
6.
Martin Piesch Stephan Reichl Michael Seidl Gbor Balzs Manfred Scheer 《Angewandte Chemie (International ed. in English)》2019,58(46):16563-16568
The reaction of [Cp′′′Co(η4‐P4)] ( 1 ) (Cp′′′=1,2,4‐tBu3C5H2) with MeNHC (MeNHC=1,3,4,5‐tetramethylimidazol‐2‐ylidene) leads through NHC‐induced phosphorus cation abstraction to the ring contraction product [(MeNHC)2P][Cp′′′Co(η3‐P3)] ( 2 ), which represents the first example of an anionic CoP3 complex. Such NHC‐induced ring contraction reactions are also applicable for triple‐decker sandwich complexes. The complexes [(Cp*Mo)2(μ,η6:6‐E6)] ( 3 a , 3 b ) (Cp*=C5Me5; E=P, As) can be transformed to the complexes [(MeNHC)2E][(Cp*M)2(μ,η3:3‐E3)(μ,η2:2‐E2)] ( 4 a , 4 b ), with 4 b representing the first structurally characterized example of an NHC‐substituted AsI cation. Further, the reaction of the vanadium complex [(Cp*V)2(μ,η6:6‐P6)] ( 5 ) with MeNHC results in the formation of the unprecedented complexes [(MeNHC)2P][(Cp*V)2(μ,η6:6‐P6)] ( 6 ), [(MeNHC)2P][(Cp*V)2(μ,η5:5‐P5)] ( 7 ) and [(Cp*V)2(μ,η3:3‐P3)(μ,η1:1‐P{MeNHC})] ( 8 ). 相似文献
7.
Martin Piesch Stephan Reichl Michael Seidl Gbor Balzs Manfred Scheer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16716-16721
Die Reaktion von [Cp′′′Co(η4‐P4)] ( 1 ) (Cp′′′=1,2,4‐tBu3C5H2) mit MeNHC (MeNHC=1,3,4,5‐tetramethylimidazol‐2‐ylidene) führt über eine NHC‐induzierte Phosphorkationen‐Abstraktion zum Ringkontraktionsprodukt [(MeNHC)2P][Cp′′′Co(η3‐P3)] ( 2 ), welches das erste Beispiel eines anionischen CoP3‐Komplexes repräsentiert. Solche von NHCs induzierten Ringkontraktionsreaktionen lassen sich ebenfalls auf Tripeldecker‐Sandwich‐Komplexe anwenden. So werden die Komplexe [(Cp*Mo)2(μ,η6:6‐E6)] ( 3 a , 3 b ) (Cp*=C5Me5; E=P, As) zu den Komplexen [(MeNHC)2E][(Cp*M)2(μ,η3:3‐E3)(μ,η2:2‐E2)] ( 4 a , 4 b ) transformiert, wobei 4 b das erste strukturell charakterisierte Beispiel eines NHC‐substituierten AsI‐Kations darstellt. Darüber hinaus führt die Reaktion des Vanadium‐Komplexes [(Cp*V)2(μ,η6:6‐P6)] ( 5 ) mit MeNHC zur Bildung der neuartigen Komplexe [(MeNHC)2P][(Cp*V)2(μ,η6:6‐P6)] ( 6 ), [(MeNHC)2P][(Cp*V)2(μ,η5:5‐P5)] ( 7 ) bzw. [(Cp*V)2(μ,η3:3‐P3)(μ,η1:1‐P{MeNHC})] ( 8 ). 相似文献
8.
Dr. Nicholas Arleth Dr. Michael T. Gamer Dr. Ralf Köppe Prof. Dr. Sergey N. Konchenko Martin Fleischmann Prof. Dr. Manfred Scheer Prof. Dr. Peter W. Roesky 《Angewandte Chemie (International ed. in English)》2016,55(4):1557-1560
Reduction of [Cp*Fe(η5‐As5)] with [Cp′′2Sm(thf)] (Cp′′=η5‐1,3‐(tBu)2C5H3) under various conditions led to [(Cp′′2Sm)(μ,η4:η4‐As4)(Cp*Fe)] and [(Cp′′2Sm)2As7(Cp*Fe)]. Both compounds are the first polyarsenides of the rare‐earth metals. [(Cp′′2Sm)(μ,η4:η4‐As4)(Cp*Fe)] is also the first d/f‐triple decker sandwich complex with a purely inorganic planar middle deck. The central As42? unit is isolobal with the 6π‐aromatic cyclobutadiene dianion (CH)42?. [(Cp′′2Sm)2As7(Cp*Fe)] contains an As73? cage, which has a norbornadiene‐like structure with two short As?As bonds in the scaffold. DFT calculations confirm all the structural observations. The As?As bond order inside the cyclo As4 ligand in [(Cp′′2Sm)(μ,η4:η4‐As4)(Cp*Fe)] was estimated to be in between an As?As single bond and a formally aromatic As42? system. 相似文献
9.
L. Weber S. Uthmann S. Kleinebekel H.‐G. Stammler A. Stammler B. Neumann 《无机化学与普通化学杂志》2000,626(8):1831-1836
Syntheses and Structures of η1‐Phosphaallyl, η1‐Arsaallyl, and η1‐Stibaallyl Iron Complexes [(η5‐C5Me5)(CO)2Fe–E(SiMe3)C(OSiMe3)=CPh2] (E = P, As, Sb) The reaction of equimolar amounts of [(η5‐C5Me5)(CO)2Fe–E(SiMe3)2] ( 1 a : E = P; 1 b : As; 1 c : Sb) and diphenylketene afforded the η1‐phosphaallyl‐, η1‐arsaallyl‐, and η1‐stibaallyl complexes [(η5‐C5Me5)(CO)2Fe–E(SiMe3)C(OSiMe3)=CPh2] ( 2 a : E = P; 2 b : As; 2 c : Sb). The molecular structures of 2 b and 2 c were elucidated by single crystal X‐ray analyses. 相似文献
10.
Dr. Jianquan Hong Prof. Dr. Lixin Zhang Kai Wang Yin Zhang Prof. Linhong Weng Prof. Xigeng Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(24):7865-7873
Three new patterns of reactivity of rare‐earth metal methylidene complexes have been established and thus have resulted in access to a wide variety of imido rare‐earth metal complexes [L3Ln3(μ2‐Me)3(μ3‐Me)(μ ‐ NR)] (L=[PhC(NC6H3iPr2‐2,6)2]?; R=Ph, Ln=Y ( 2 a ), Lu ( 2 b ); R=2,6‐Me2C6H3, Ln=Y ( 3 a ), Lu ( 3 b ); R=p‐ClC6H4, Ln=Y ( 4 a ), Lu ( 4 b ); R=p‐MeOC6H4, Ln=Y ( 5 a ), Lu ( 5 b ); R=Me2CHCH2CH2, Ln=Y ( 6 a ), Lu ( 6 b )) and [{L3Lu3(μ2‐Me)3(μ3‐Me)}2(μ ‐ NR′N)] (R′=(CH2)6 ( 7 b ), (C6H4)2 ( 8 b )). Complex 2 b was treated with an excess of CO2 to give the corresponding carboxylate complex [L3Lu3(μ‐η1:η1‐O2CCH3)3(μ‐η1:η2‐O2C‐CH3)(μ‐η1:η1:η2‐O2CNPh)] ( 9 b ) easily. Complex 2 a could undergo the selective μ3‐Me abstraction reaction with phenyl acetylene to give the mixed imido/alkynide complex [L3Y3(μ2‐Me)3(μ3‐η1:η1:η3‐NPh)(μ3‐C?CPh)] ( 10 a ) in high yield. Treatment of 2 with one equivalent of thiophenol gave the selective μ3‐methyl‐abstracted products [L3Ln3(μ2‐Me)3(μ3‐η1:η1:η3‐NPh)(μ3‐SPh)] (Ln=Y ( 11 a ); Lu ( 11 b ). All new complexes have been characterized by elemental analysis, NMR spectroscopy, and most of the structures confirmed by X‐ray diffraction. 相似文献
11.
Martin Piesch Dr. Fabian Dielmann Stephan Reichl Prof. Dr. Manfred Scheer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(7):1518-1524
A systematic study on the reactivity of the triple-decker complex [(Cp’’’Co)2(μ,η4:η4-C7H8)] ( A ) (Cp’’’=1,2,4-tritertbutyl-cyclopentadienyl) towards sandwich complexes containing cyclo-P3, cyclo-P4, and cyclo-P5 ligands under mild conditions is presented. The heterobimetallic triple-decker sandwich complexes [(Cp*Fe)(Cp’’’Co)(μ,η5:η4-P5)] ( 1 ) and [(Cp’’’Co)(Cp’’’Ni)(μ,η3:η3-P3)] ( 3 ) (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl) were synthesized and fully characterized. In solution, these complexes exhibit a unique fluxional behavior, which was investigated by variable temperature NMR spectroscopy. The dynamic processes can be blocked by coordination to {W(CO)5} fragments, leading to the complexes [(Cp*Fe)(Cp’’’Co)(μ3,η5:η4:η1-P5){W(CO)5}] ( 2 a ), [(Cp*Fe)(Cp’’’Co)(μ4,η5:η4:η1:η1-P5){(W(CO)5)2}] ( 2 b ), and [(Cp’’’Co)(Cp’’’Ni)(μ3,η3:η2:η1-P3){W(CO)5}] ( 4 ), respectively. The thermolysis of 3 leads to the tetrahedrane complex [(Cp’’’Ni)2(μ,η2:η2-P2)] ( 5 ). All compounds were fully characterized using single-crystal X-ray structure analysis, NMR spectroscopy, mass spectrometry, and elemental analysis. 相似文献
12.
Piano‐stool‐shaped platinum group metal compounds, stable in the solid state and in solution, which are based on 2‐(5‐phenyl‐1H‐pyrazol‐3‐yl)pyridine ( L ) with the formulas [(η6‐arene)Ru( L )Cl]PF6 {arene = C6H6 ( 1 ), p‐cymene ( 2 ), and C6Me6, ( 3 )}, [(η6‐C5Me5)M( L )Cl]PF6 {M = Rh ( 4 ), Ir ( 5 )}, and [(η5‐C5H5)Ru(PPh3)( L )]PF6 ( 6 ), [(η5‐C5H5)Os(PPh3)( L )]PF6 ( 7 ), [(η5‐C5Me5)Ru(PPh3)( L )]PF6 ( 8 ), and [(η5‐C9H7)Ru(PPh3)( L )]PF6 ( 9 ) were prepared by a general method and characterized by NMR and IR spectroscopy and mass spectrometry. The molecular structures of compounds 4 and 5 were established by single‐crystal X‐ray diffraction. In each compound the metal is connected to N1 and N11 in a k2 manner. 相似文献
13.
The mononuclear amidinate complexes [(η6‐cymene)‐RuCl( 1a )] ( 2 ) and [(η6‐C6H6)RuCl( 1b )] ( 3 ), with the trimethylsilyl‐ethinylamidinate ligands [Me3SiC≡CC(N‐c‐C6H11)2]– ( 1a– ) and[Me3SiC≡CC(N‐i‐C3H7)2]– ( 1b– ) were synthesized in high yields by salt metathesis. In addition, the related phosphane complexes[(η5‐C5H5)Ru(PPh3)( 1b )] ( 4a ) [(η5‐C5Me5)Ru(PPh3)( 1b )] ( 4b ), and [(η6‐C6H6)Ru(PPh3)( 1b )](BF4) ( 5 ‐BF4) were prepared by ligand exchange reactions. Investigations on the removal of the trimethyl‐silyl group using [Bu4N]F resulted in the isolation of [(η6‐C6H6)Ru(PPh3){(N‐i‐C3H7)2CC≡CH}](BF4) ( 6 ‐BF4) bearing a terminal alkynyl hydrogen atom, while 2 and 3 revealed to yield intricate reaction mixtures. Compounds 1a / b to 6 ‐BF4 were characterized by multinuclear NMR (1H, 13C, 31P) and IR spectroscopy and elemental analyses, including X‐ray diffraction analysis of 1b , 2 , and 3 . 相似文献
14.
Hans‐Christian Bttcher Marion Graf Kurt Merzweiler Christoph Wagner 《无机化学与普通化学杂志》2000,626(6):1335-1340
Coordinatively Unsaturated Diruthenium Complexes: Synthesis and X‐ray Crystal Structures of [Ru2(CO)3L(μ‐η1 : η2‐C≡CPh)(μ‐PtBu2)(μ‐Ph2PCH2PPh2)] (L = CO, PnBu3) [Ru2(CO)4(μ‐H)(μ‐PtBu2)(μ‐dppm)] ( 1 ) reacts with several phosphines (L) in refluxing toluene under substitution of one carbonyl ligand and yields the compounds [Ru2(CO)3L(μ‐H)(μ‐PtBu2)(μ‐dppm)] (L = PnBu3, 2 a ; L = PCy2H, 2 b ; L = dppm‐P, 2 c ; dppm = Ph2PCH2PPh2). The reactivity of 1 as well as the activated complexes 2 a – c towards phenylethyne was studied. Thus 1 , 2 a and 2 b , respectively, react with PhC≡CH in refluxing toluene with elimination of dihydrogen to the acetylide‐bridged complexes [Ru2(CO)4(μ‐η1 : η2‐C≡CPh)(μ‐PtBu2)(μ‐dppm)] ( 3 ) and [Ru2(CO)3L(μ‐η1 : η2‐C≡CPh)(μ‐PtBu2)(μ‐dppm)] ( 4 a and 4 b ). The molecular structures of 3 and 4 a were determined by crystal structure analyses. 相似文献
15.
Dr. Fabian Spitzer Dr. Gábor Balázs Dr. Christian Graßl M. Sc. Martin Keilwerth Prof. Dr. Karsten Meyer Prof. Dr. Manfred Scheer 《Angewandte Chemie (International ed. in English)》2018,57(28):8760-8764
In a systematic study of the activation of As4, three [LCo(tol)] (L=β‐diiminato) complexes have revealed different steric and electronic influences. 2,6‐Diisopropylphenyl (Dipp) and 2,6‐dimethylphenyl (dmp) flanking groups were used, one of the ligands with H backbone substituents (β‐dialdiminate L0) and two with Me substituents (β‐diketiminates L3 and L1). In the reaction with As4, different dinuclear products [(LCo)2As4] (LM=L0 ( 1 ), L1 ( 2 ), L3 ( 3 )) were isolated, with all showing differently shaped [Co2As4] cores in the solid state: octahedral in 1 , prismatic in 2 , and asterane‐like in 3 . Thermal treatment of 3 leads to the abstraction of one arsenic atom to yield [(L3Co)2As3] ( 4 ). All products were comprehensively characterized by single‐crystal X‐ray diffraction, FD‐MS, and 1H NMR spectroscopy. A rational explanation for the different reactivity is also proposed and DFT calculations shed light on the nature of the highly flexible [Co2As4] cores. 相似文献
16.
Dr. Robert Langer Dr. Mark A. Iron Dr. Leonid Konstantinovski Dr. Yael Diskin‐Posner Dr. Gregory Leitus Yehoshoa Ben‐David Prof. Dr. David Milstein 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(23):7196-7209
The new, structurally characterized hydrido carbonyl tetrahydridoborate iron pincer complex [(iPr‐PNP)Fe(H)(CO)(η1‐BH4)] ( 1 ) catalyzes the base‐free hydrogenation of ketones to their corresponding alcohols employing only 4.1 atm hydrogen pressure. Turnover numbers up to 1980 at complete conversion of ketone were reached with this system. Treatment of 1 with aniline (as a BH3 scavenger) resulted in a mixture of trans‐[(iPr‐PNP)Fe(H)2(CO)] ( 4 a ) and cis‐[(iPr‐PNP)Fe(H)2(CO)] ( 4 b ). The dihydrido complexes 4 a and 4 b do not react with acetophenone or benzaldehyde, indicating that these complexes are not intermediates in the catalytic reduction of ketones. NMR studies indicate that the tetrahydridoborate ligand in 1 dissociates prior to ketone reduction. DFT calculations show that the mechanism of the iron‐catalyzed hydrogenation of ketones involves alcohol‐assisted aromatization of the dearomatized complex [(iPr‐PNP*)Fe(H)(CO)] ( 7 ) to initially give the Fe0 complex [(iPr‐PNP)Fe(CO)] ( 21 ) and subsequently [(iPr‐PNP)Fe(CO)(EtOH)] ( 38 ). Concerted coordination of acetophenone and dual hydrogen‐atom transfer from the PNP arm and the coordinated ethanol to, respectively, the carbonyl carbon and oxygen atoms, leads to the dearomatized complex [(iPr‐PNP*)Fe(CO)(EtO)(MeCH(OH)Ph)] ( 32 ). The catalyst is regenerated by release of 1‐phenylethanol, followed by dihydrogen coordination and proton transfer to the coordinated ethoxide ligand. 相似文献
17.
M. Sc. Fabian Spitzer Prof. Dr. Marek Sierka Prof. Mario Latronico Prof. Dr. Piero Mastrorilli Dr. Alexander V. Virovets Prof. Dr. Manfred Scheer 《Angewandte Chemie (International ed. in English)》2015,54(14):4392-4396
By the reaction of [NacnacCuCH3CN] with white phosphorus (P4) and yellow arsenic (As4), the stabilization and enclosure of the intact E4 tetrahedra are realized and the disubstituted complexes [(NacnacCu)2(μ,η2:2‐E4)] ( 1 a : E=P, 1 b : E=As) are formed. The mono‐substituted complex [NacnacCu(η2‐P4)] ( 2 ), was detected by the exchange reaction of 1 a with P4 and was only isolated using low‐temperature work‐up. All products were comprehensively spectroscopically and crystallographically characterized. The bonding situation in the products as intact E4 units (E=P, As) was confirmed by theory and was experimentally proven by the pyridine promoted release of the bridging E4 tetrahedra in 1 . 相似文献
18.
Xuting Wang Dr. Yanxia Zhao Shida Gong Prof. Bin Liu Prof. Qian‐Shu Li Prof. Ji‐Hu Su Prof. Biao Wu Prof. Xiao‐Juan Yang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(38):13302-13310
Reactions of the dimeric cobalt complex [(L?Co)2] ( 1 , L=[(2,6‐iPr2C6H3)NC(Me)]2) with polyarenes afforded a series of mononuclear and dinuclear complexes: [LCo(η4‐anthracene)] ( 2 ), [LCo(μ‐η4:η4‐naphthalene)CoL] ( 3 ), and [LCo(μ‐η4:η4‐phenanthrene)CoL] ( 4 ). The pyrene complexes [{Na2(Et2O)2}{LCo(μ‐η3:η3‐pyrene)CoL}] ( 5 ) and [{Na2(Et2O)3}{LCo(η3‐pyrene)}] ( 6 ) were obtained by treating precursor 1 with pyrene followed by reduction with Na metal. These complexes contain three potential redox active centers: the cobalt metal and both α‐diimine and polyarene ligands. Through a combination of X‐ray crystallography, EPR spectroscopy, magnetic susceptibility measurement, and DFT computations, the electronic configurations of these complexes were studied. It was determined that complexes 2 – 4 have a high‐spin CoI center coupled with a radical α‐diimine ligand and a neutral polyarene ligand. Whereas, the ligand L in complexes 5 and 6 has been further reduced to the dianion, the cobalt remains in a formal (I) oxidation state, and the pyrene molecule is either neutral or monoanionic. 相似文献
19.
Helena Brake Eugenia Peresypkina Alexander V. Virovets Martin Piesch Werner Kremer Lisa Zimmermann Christian Klimas Manfred Scheer 《Angewandte Chemie (International ed. in English)》2020,59(37):16241-16246
In a high‐yield one‐pot synthesis, the reactions of [Cp*M(η5‐P5)] (M=Fe ( 1 ), Ru ( 2 )) with I2 resulted in the selective formation of [Cp*MP6I6]+ salts ( 3 , 4 ). The products comprise unprecedented all‐cis tripodal triphosphino‐cyclotriphosphine ligands. The iodination of [Cp*Fe(η5‐As5)] ( 6 ) gave, in addition to [Fe(CH3CN)6]2+ salts of the rare [As6I8]2? (in 7 ) and [As4I14]2? (in 8 ) anions, the first di‐cationic Fe‐As triple decker complex [(Cp*Fe)2(μ,η5:5‐As5)][As6I8] ( 9 ). In contrast, the iodination of [Cp*Ru(η5‐As5)] ( 10 ) did not result in the full cleavage of the M?As bonds. Instead, a number of dinuclear complexes were obtained: [(Cp*Ru)2(μ,η5:5‐As5)][As6I8]0.5 ( 11 ) represents the first Ru‐As5 triple decker complex, thus completing the series of monocationic complexes [(CpRM)2(μ,η5:5‐E5)]+ (M=Fe, Ru; E=P, As). [(Cp*Ru)2As8I6] ( 12 ) crystallizes as a racemic mixture of both enantiomers, while [(Cp*Ru)2As4I4] ( 13 ) crystallizes as a symmetric and an asymmetric isomer and features a unique tetramer of {AsI} arsinidene units as a middle deck. 相似文献
20.
Direct Evidence for a [4+2] Cycloaddition Mechanism of Alkynes to Tantallacyclopentadiene on Dinuclear Tantalum Complexes as a Model of Alkyne Cyclotrimerization
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Keishi Yamamoto Dr. Hayato Tsurugi Prof. Dr. Kazushi Mashima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(32):11369-11377
A dinuclear tantalum complex, [Ta2Cl6(μ‐C4Et4)] ( 2 ), bearing a tantallacyclopentadiene moiety, was synthesized by treating [(η2‐EtC?CEt)TaCl3(DME)] ( 1 ) with AlCl3. Complex 2 and its Lewis base adducts, [Ta2Cl6(μ‐C4Et4)L] (L=THF ( 3 a ), pyridine ( 3 b ), THT ( 3 c )), served as more active catalysts for cyclotrimerization of internal alkynes than 1 . During the reaction of 3 a with 3‐hexyne, we isolated [Ta2Cl4(μ‐η4:η4‐C6Et6)(μ‐η2:η2‐EtC?CEt)] ( 4 ), sandwiched by a two‐electron reduced μ‐η4:η4‐hexaethylbenzene and a μ‐η2:η2‐3‐hexyne ligand, as a product of an intermolecular cyclization between the metallacyclopentadiene moiety and 3‐hexyne. The formation of arene complexes [Ta2Cl4(μ‐η4:η4‐C6Et4Me2)(μ‐η2:η2‐Me3SiC?CSiMe3)] ( 7 b ) and [Ta2Cl4(μ‐η4:η4‐C6Et4RH)(μ‐η2:η2‐Me3SiC?CSiMe3)] (R=nBu ( 8 a ), p‐tolyl ( 8 b )) by treating [Ta2Cl4(μ‐C4Et4)(μ‐η2:η2‐Me3SiC?CSiMe3)] ( 6 ) with 2‐butyne, 1‐hexyne, and p‐tolylacetylene without any isomers, at room temperature or low temperature were key for clarifying the [4+2] cycloaddition mechanism because of the restricted rotation behavior of the two‐electron reduced arene ligands without dissociation from the dinuclear tantalum center. 相似文献