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1.
Dr. Mathew D. Anker Dr. Claire L. McMullin Dr. Nasir A. Rajabi Prof. Dr. Martyn P. Coles 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(31):12906-12910
[K{Al(NONDipp)}]2 (NONDipp=[O(SiMe2NDipp)2]2−, Dipp=2,6-iPr2C6H3) reacts with CS2 to afford the trithiocarbonate species [K(OEt2)][Al(NONDipp)(CS3)] 1 or the ethenetetrathiolate complex, [K{Al(NONDipp)(S2C)}]2 [ 3 ]2. The dimeric alumoxane [K{Al(NONDipp)(O)}]2 reacts with carbon monoxide to afford the oxygen analogue of 3 , [K{Al(NONDipp)(O2C)}]2 [ 4 ]2 containing the hitherto unknown ethenetetraolate ligand, [C2O4]4−. 相似文献
2.
Mathew D. Anker Claire L. McMullin Nasir A. Rajabi Martyn P. Coles 《Angewandte Chemie (International ed. in English)》2020,59(31):12806-12810
[K{Al(NONDipp)}]2 (NONDipp=[O(SiMe2NDipp)2]2?, Dipp=2,6‐iPr2C6H3) reacts with CS2 to afford the trithiocarbonate species [K(OEt2)][Al(NONDipp)(CS3)] 1 or the ethenetetrathiolate complex, [K{Al(NONDipp)(S2C)}]2 [ 3 ]2. The dimeric alumoxane [K{Al(NONDipp)(O)}]2 reacts with carbon monoxide to afford the oxygen analogue of 3 , [K{Al(NONDipp)(O2C)}]2 [ 4 ]2 containing the hitherto unknown ethenetetraolate ligand, [C2O4]4?. 相似文献
3.
Simon J. Bonyhady Cameron Jones Prof. Sharanappa Nembenna Dr. Andreas Stasch Dr. Alison J. Edwards Dr. Garry J. McIntyre Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(3):938-955
The preparation and characterization of a series of magnesium(II) iodide complexes incorporating β‐diketiminate ligands of varying steric bulk and denticity, namely, [(ArNCMe)2CH]? (Ar=phenyl, (PhNacnac), mesityl (MesNacnac), or 2,6‐diisopropylphenyl (Dipp, DippNacnac)), [(DippNCtBu)2CH]? (tBuNacnac), and [(DippNCMe)(Me2NCH2CH2NCMe)CH]? (DmedaNacnac) are reported. The complexes [(PhNacnac)MgI(OEt2)], [(MesNacnac)MgI(OEt2)], [(DmedaNacnac)MgI(OEt2)], [(MesNacnac)MgI(thf)], [(DippNacnac)MgI(thf)], [(tBuNacnac)MgI], and [(tBuNacnac)MgI(DMAP)] (DMAP=4‐dimethylaminopyridine) were shown to be monomeric by X‐ray crystallography. In addition, the related β‐diketiminato beryllium and calcium iodide complexes, [(MesNacnac)BeI] and [{(DippNacnac)CaI(OEt2)}2] were prepared and crystallographically characterized. The reductions of all metal(II) iodide complexes by using various reagents were attempted. In two cases these reactions led to the magnesium(I) dimers, [(MesNacnac)MgMg(MesNacnac)] and [(tBuNacnac)MgMg(tBuNacnac)]. The reduction of a 1:1 mixture of [(DippNacnac)MgI(OEt2)] and [(MesNacnac)MgI(OEt2)] with potassium gave a low yield of the crystallographically characterized complex [(DippNacnac)Mg(μ‐H)(μ‐I)Mg(MesNacnac)]. All attempts to form beryllium(I) or calcium(I) dimers by reductions of [(MesNacnac)BeI], [{(DippNacnac)CaI(OEt2)}2], or [{(tBuNacnac)CaI(thf)}2] have so far been unsuccessful. The further reactivity of the magnesium(I) complexes [(MesNacnac)MgMg(MesNacnac)] and [(tBuNacnac)MgMg(tBuNacnac)] towards a variety of Lewis bases and unsaturated organic substrates was explored. These studies led to the complexes [(MesNacnac)Mg(L)Mg(L)(MesNacnac)] (L=THF or DMAP), [(MesNacnac)Mg(μ‐AdN6Ad)Mg(MesNacnac)] (Ad=1‐adamantyl), [(tBuNacnac)Mg(μ‐AdN6Ad)Mg(tBuNacnac)], and [(MesNacnac)Mg(μ‐tBu2N2C2O2)Mg(MesNacnac)] and revealed that, in general, the reactivity of the magnesium(I) dimers is inversely proportional to their steric bulk. The preparation and characterization of [(tBuNacnac)Mg(μ‐H)2Mg(tBuNacnac)] has shown the compound to have different structural and physical properties to [(tBuNacnac)MgMg(tBuNacnac)]. Treatment of the former with DMAP has given [(tBuNacnac)Mg(H)(DMAP)], the X‐ray crystal structure of which disclosed it to be the first structurally authenticated terminal magnesium hydride complex. Although attempts to prepare [(MesNacnac)Mg(μ‐H)2Mg(MesNacnac)] were not successful, a neutron diffraction study of the corresponding magnesium(I) complex, [(MesNacnac)MgMg(MesNacnac)] confirmed that the compound is devoid of hydride ligands. 相似文献
4.
Oliver J. Cooper Dr. David P. Mills Dr. Jonathan McMaster Dr. Floriana Tuna Prof. Eric. J. L. McInnes Dr. William Lewis Prof. Alexander J. Blake Dr. Stephen T. Liddle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7071-7083
Treatment of [K(BIPMMesH)] (BIPMMes={C(PPh2NMes)2}2?; Mes=C6H2‐2,4,6‐Me3) with [UCl4(thf)3] (1 equiv) afforded [U(BIPMMesH)(Cl)3(thf)] ( 1 ), which generated [U(BIPMMes)(Cl)2(thf)2] ( 2 ), following treatment with benzyl potassium. Attempts to oxidise 2 resulted in intractable mixtures, ligand scrambling to give [U(BIPMMes)2] or the formation of [U(BIPMMesH)(O)2(Cl)(thf)] ( 3 ). The complex [U(BIPMDipp)(μ‐Cl)4(Li)2(OEt2)(tmeda)] ( 4 ) (BIPMDipp={C(PPh2NDipp)2}2?; Dipp=C6H3‐2,6‐iPr2; tmeda=N,N,N′,N′‐tetramethylethylenediamine) was prepared from [Li2(BIPMDipp)(tmeda)] and [UCl4(thf)3] and, following reflux in toluene, could be isolated as [U(BIPMDipp)(Cl)2(thf)2] ( 5 ). Treatment of 4 with iodine (0.5 equiv) afforded [U(BIPMDipp)(Cl)2(μ‐Cl)2(Li)(thf)2] ( 6 ). Complex 6 resists oxidation, and treating 4 or 5 with N‐oxides gives [{U(BIPMDippH)(O)2‐ (μ‐Cl)2Li(tmeda)] ( 7 ) and [{U(BIPMDippH)(O)2(μ‐Cl)}2] ( 8 ). Treatment of 4 with tBuOLi (3 equiv) and I2 (1 equiv) gives [U(BIPMDipp)(OtBu)3(I)] ( 9 ), which represents an exceptionally rare example of a crystallographically authenticated uranium(VI)–carbon σ bond. Although 9 appears sterically saturated, it decomposes over time to give [U(BIPMDipp)(OtBu)3]. Complex 4 reacts with PhCOtBu and Ph2CO to form [U(BIPMDipp)(μ‐Cl)4(Li)2(tmeda)(OCPhtBu)] ( 10 ) and [U(BIPMDipp)(Cl)(μ‐Cl)2(Li)(tmeda)(OCPh2)] ( 11 ). In contrast, complex 5 does not react with PhCOtBu and Ph2CO, which we attribute to steric blocking. However, complexes 5 and 6 react with PhCHO to afford (DippNPPh2)2C?C(H)Ph ( 12 ). Complex 9 does not react with PhCOtBu, Ph2CO or PhCHO; this is attributed to steric blocking. Theoretical calculations have enabled a qualitative bracketing of the extent of covalency in early‐metal carbenes as a function of metal, oxidation state and the number of phosphanyl substituents, revealing modest covalent contributions to U?C double bonds. 相似文献
5.
Dr. Ryan J. Schwamm Prof. Michael S. Hill Han-Ying Liu Dr. Mary F. Mahon Dr. Claire L. McMullin Dr. Nasir A. Rajabi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(60):14971-14980
The seven-membered cyclic potassium alumanyl species, [{SiNMes}AlK]2 [{SiNMes}={CH2SiMe2N(Mes)}2; Mes=2,4,6-Me3C6H2], which adopts a dimeric structure supported by flanking K-aryl interactions, has been isolated either by direct reduction of the iodide precursor, [{SiNMes}AlI], or in a stepwise manner via the intermediate dialumane, [{SiNMes}Al]2. Although the intermediate dialumane has not been observed by reduction of a Dipp-substituted analogue (Dipp=2,6-i-Pr2C6H3), partial oxidation of the potassium alumanyl species, [{SiNDipp}AlK]2, where {SiNDipp}={CH2SiMe2N(Dipp)}2, provided the extremely encumbered dialumane [{SiNDipp}Al]2. [{SiNDipp}AlK]2 reacts with toluene by reductive activation of a methyl C(sp3)-H bond to provide the benzyl hydridoaluminate, [{SiNDipp}AlH(CH2Ph)]K, and as a nucleophile with BPh3 and RN=C=NR (R=i-Pr, Cy) to yield the respective Al-B- and Al-C-bonded potassium aluminaborate and alumina-amidinate products. The dimeric structure of [{SiNDipp}AlK]2 can be disrupted by partial or complete sequestration of potassium. Equimolar reactions with 18-crown-6 result in the corresponding monomeric potassium alumanyl, [{SiNDipp}Al−K(18-cr-6)], which provides a rare example of a direct Al−K contact. In contrast, complete encapsulation of the potassium cation of [{SiNDipp}AlK]2, either by an excess of 18-cr-6 or 2,2,2-cryptand, allows the respective isolation of bright orange charge-separated species comprising the ‘free’ [{SiNDipp}Al]− alumanyl anion. Density functional theory (DFT) calculations performed on this moiety indicate HOMO-LUMO energy gaps in the of order 200–250 kJ mol−1. 相似文献
6.
Bi−P Bond Homolysis as a Route to Reduced Bismuth Compounds and Reversible Activation of P4
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Ryan J. Schwamm Dr. Matthias Lein Dr. Martyn P. Coles Dr. Christopher M. Fitchett 《Angewandte Chemie (International ed. in English)》2016,55(47):14798-14801
Bismuth diphenylphosphanides Bi(NONR)(PPh2) (NONR=[O(SiMe2NR)2], R=tBu, 2,6‐iPr2C6H3, Aryl) undergo facile decomposition via single‐electron processes to form reduced Bi and P species. The corresponding derivatives Bi(NONR)(PCy2) are stable. Reaction of the isolated BiII radical .Bi(NONAr) with white phosphorus (P4) proceeds with the reversible and selective activation of a single P?P bond to afford the bimetallic μ,η1:1‐bicyclo[1.1.0]tetraphosphabutane compound. 相似文献
7.
《Journal of Coordination Chemistry》2012,65(24):4148-4163
AbstractWe report the reactions of imidazolin-2-iminato titanium complexes [(ImRN)Ti(NMe2)3] (R = Mes, 2b; R = Dipp, 2c; Mes = mesityl, Dipp = 2,6-diisopropylphenyl) with 2,6-diisopropylaniline in a 1:3 molar ratio to yield the titanium imido complexes of composition [(ImRNH)Ti = N(Dipp)(HNDipp)2] (R = Mes, 3b; R = Dipp, 3c) in good yield by the Ti-Niminato bond cleavage at 60 °C. In contrast, the reaction of [(ImRN)Ti(NMe2)3] with 2,6-diisopropylaniline in a 1:1 molar ratio afforded mono-substituted products [(ImRN)Ti(NMe2)2(HNDipp)] (R = Mes, 4b; R = Dipp, 4c) in good yield. The reaction of [(ImRN)Ti(NMe2)3] with the iminopyrrole ligand [2-(2,6-iPr2C6H3-N = CH)C4H3NH] (NDippPyH) in a 1:1 ratio afforded mixed ligands, titanium complexes [(ImRN)Ti(NMe2)2(NDipp-Py)] (R = tBu, 5a; R = Dipp, 5c) with imidazolin-2-iminato and iminopyrrolide ligands. Molecular structures of 3b, 3c, 4c, 5a, and 5c were determined by single-crystal X-ray analysis. The solid-state structures of 3b and 3c clearly indicate the formation of true Ti = N double bonds, measuring 1.730(2) Å and 1.727(1) Å, respectively. The solid-state structures of 5a and 5c reveal the formation of five-coordinate titanium complexes. 相似文献
8.
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
9.
Christoph Wallach Dr. Felix S. Geitner Dr. Wilhelm Klein Prof. Dr. Thomas F. Fässler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(53):12349-12356
The synthetic approach towards molecules that contain Ge atoms with oxidation state 0, and which are exclusively connected to other Ge atoms, is explored by using anionic clusters extracted from binary solids. Besides providing a novel variable method for the introduction of alkenyl moieties to [Ge9] cluster compounds, this work expands the spectrum of mixed-functionalized [Ge9] cluster anions, which are suitable for the straightforward synthesis of zwitterionic compounds upon coordination to metal cations. In detail, the synthesis of a series of mixed-functionalized [Ge9] clusters is reported, including [Ge9{Si(TMS)3}3PRRI] (R=tBu, RI=(CH2)3CH=CH2; 2 ) and [Ge9{Si(TMS)3}2PRRI]− (R and RI: alkyl, alkenyl, aryl, aminoalkyl; 3 a to 11 a , TMS: (trimethyl)silyl). In 2 and 3 a , pentenyl functionalization of the [Ge9] clusters was achieved by reaction of the novel chlorophosphine tBu{(CH2)3CH=CH2}PCl ( 1 ) with silylated [Ge9] clusters. Furthermore, the reactivity of the cluster anions 3 a to 11 a towards NHCDippMCl (NHCDipp=1,3-di(2,6-diisopropylphenyl)imidazolylidine; M=Cu, Ag) showed a dependency on the steric demand of the phosphine either zwitterions ( 3 -MNHCDipp to 7 -MNHCDipp) featuring P–M interactions are formed, or Ge–M coordination ( 8 -MNHCDipp to 11 -MNHCDipp) occurs. For M=Ag, the formation of zwitterionic complexes was unequivocally proven by NMR investigations showing 1J(31P-107Ag/109Ag) spin-spin coupling. 相似文献
10.
Ravi Yadav Thomas Simler Bhupendra Goswami Christoph Schoo Ralf Kppe Subhayan Dey Peter W. Roesky 《Angewandte Chemie (International ed. in English)》2020,59(24):9443-9447
A route to directly access mixed Al–Fe polyphosphide complexes was developed. The reactivity of pentaphosphaferrocene, [Cp*Fe(η5‐P5)] (Cp*=C5Me5), with two different low‐valent aluminum compounds was investigated. The steric and electronic environment around the [AlI] centre are found to be crucial for the formation of the resulting Al–Fe polyphosphides. Reaction with the sterically demanding [Dipp‐BDIAlI] (Dipp‐BDI={[2,6‐iPr2C6H3NCMe]2CH}?) resulted in the first Al‐based neutral triple‐decker type polyphosphide complex. For [(Cp*AlI)4], an unprecedented regioselective insertion of three [Cp*AlIII]2+ moieties into two adjacent P?P bonds of the cyclo‐P5 ring of [Cp*Fe(η5‐P5)] was observed. The regioselectivity of the insertion reaction could be rationalized by isolating an analogue of the reaction intermediate stabilized by a strong σ‐donor carbene. 相似文献
11.
Matthew J. Evans Mathew D. Anker Claire L. McMullin Samuel E. Neale Nasir A. Rajabi Martyn P. Coles 《Chemical science》2022,13(16):4635
Multiply-bonded main group metal compounds are of interest as a new class of reactive species able to activate and functionalize a wide range of substrates. The aluminium sulfido compound K[Al(NONDipp)(S)] (NONDipp = [O(SiMe2NDipp)2]2−, Dipp = 2,6-iPr2C6H3), completing the series of [Al(NONDipp)(E)]− anions containing Al–E{16} multiple bonds (E{16} = O, S, Se, Te), was accessed via desulfurisation of K[Al(NONDipp)(S4)] using triphenylphosphane. The crystal structure showed a tetrameric aggregate joined by multiple K⋯S and K⋯π(arene) interactions that were disrupted by the addition of 2.2.2-cryptand to form the separated ion pair, [K(2.2.2-crypt)][Al(NONDipp)(S)]. Analysis of the anion using density functional theory (DFT) confirmed multiple-bond character in the Al–S group. The reaction of the sulfido and selenido anions K[Al(NONDipp)(E)] (E = S, Se) with CO2 afforded K[Al(NONDipp)(κ2E,O-EC{O}O)] containing the thio- and seleno-carbonate groups respectively, consistent with a [2 + 2]-cycloaddition reaction and C–E bond formation. An analogous cycloaddition reaction took place with benzophenone affording compounds containing the diphenylsulfido- and diphenylselenido-methanolate ligands, [κ2E,O-EC{O}Ph2]2−. In contrast, when K[Al(NONDipp)(E)] (E = S, Se) was reacted with benzaldehyde, two equivalents of substrate were incorporated into the product accompanied by formation of a second C–E bond and complete cleavage of the Al–E{16} bonds. The products contained the hitherto unknown κ2O,O-thio- and κ2O,O-seleno-bis(phenylmethanolate) ligands, which were exclusively isolated as the cis-stereoisomers. The mechanisms of these cycloaddition reactions were investigated using DFT methods.Reaction of Al–E (E = S, Se) multiple bonds with C O functionalities generates new C–E bonds. 相似文献
12.
Synthesis and EPR/UV/Vis‐NIR Spectroelectrochemical Investigation of a Persistent Phosphanyl Radical Dication
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Kai Schwedtmann Stephen Schulz Felix Hennersdorf Prof. Dr. Thomas Strassner Dr. Evgenia Dmitrieva Prof. Dr. Jan J. Weigand 《Angewandte Chemie (International ed. in English)》2015,54(38):11054-11058
The reaction of the bis(imidazoliumyl)‐substituted PI cation [(2‐ImDipp)P(4‐ImDipp)]+ ( 10 +) (2‐Im=imidazolium‐2‐yl; 4‐Im=imidazolium‐4‐yl; Dipp=2,6‐di‐isopropylphenyl) with trifluoromethanesulfonic acid (HOTf) or methyl trifluoromethylsulfonate (MeOTf) yields the corresponding protonated [(2‐ImDipp)PH(4‐ImDipp)]2+ ( 11 2+) and methylated [(2‐ImDipp)PMe(4‐ImDipp)]2+ ( 12 2+) dications, respectively. EPR/UV/Vis‐NIR spectroelectrochemical investigation of the low‐coordinated PI cation 10 + predicted a stable and “bottleable” P‐centered radical dication [(2‐ImDipp)P(4‐ImDipp)]2+. ( 13 2+.). The reaction of 10 + with the nitrosyl salt NO[OTf] yields the persistent phosphanyl radical dication 13 2+. as triflate salt in crystalline form. Quantum chemical investigation revealed an exceptional high spin density at the P atom. 相似文献
13.
Synthesis and Structural Characterization of Magnesium‐Substituted Polystibides [(LMg)4Sb8]
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Dr. Chelladurai Ganesamoorthy Dr. Christoph Wölper Dr. Anton S. Nizovtsev Prof. Dr. Stephan Schulz 《Angewandte Chemie (International ed. in English)》2016,55(13):4204-4209
Redox reactions of [(L1,2Mg)2] and Sb2R4 (R=Me, Et) yielded the first Mg‐substituted realgar‐type Sb8 polystibides [(L1,2Mg)4(μ4,η2:2:2:2‐Sb8)] (L1=HC[C(Me)N(2,4,6‐Me3C6H2)]2, L2=HC[C(Me)N(2,6‐i‐Pr2C6H3)]2). Compounds [(L1,2Mg)2] serve both as reducing agents, initiating the cleavage of the Sb?C bonds, and as stabilizers for the resulting Sb8 polyanion. The polystibides were characterized by NMR and IR spectroscopies, elemental analysis, and X‐ray structure analysis. In addition, results from quantum chemical calculations are presented. 相似文献
14.
Four‐Membered Heterometallacyclic d0 and d1 Complexes of Group 4 Metallocenes with Amidato Ligands
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Dr. Martin Haehnel Jacqueline B. Priebe Jacky C.‐H. Yim Dr. Anke Spannenberg Prof. Dr. Angelika Brückner Prof. Dr. Laurel L. Schafer Prof. Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(25):7752-7758
A study of the coordination chemistry of different amidato ligands [(R)N?C(Ph)O] (R=Ph, 2,6‐diisopropylphenyl (Dipp)) at Group 4 metallocenes is presented. The heterometallacyclic complexes [Cp2M(Cl){κ2‐N,O‐(R)N?C(Ph)O}] M=Zr, R=Dipp ( 1 a ), Ph ( 1 b ); M=Hf, R=Ph ( 2 )) were synthesized by reaction of [Cp2MCl2] with the corresponding deprotonated amides. Complex 1 a was also prepared by direct deprotonation of the amide with Schwartz reagent [Cp2Zr(H)Cl]. Salt metathesis reaction of [Cp2Zr(H)Cl] with deprotonated amide [(Dipp)N?C(Ph)O] gave the zirconocene hydrido complex [Cp2M(H){κ2‐N,O‐(Dipp)N?C(Ph)O}] ( 3 ). Reaction of 1 a with Mg did not result in the desired Zr(III) complex but in formation of Mg complex [(py)3Mg(Cl) {κ2‐N,O‐(Dipp)N?C(Ph)O}] ( 4 ; py=pyridine). The paramagnetic complexes [Cp′2Ti{κ2‐N,O‐(R)N?C(Ph)O}] (Cp′=Cp, R=Ph ( 7 a ); Cp′=Cp, R=Dipp ( 7 b ); Cp′=Cp*, R=Ph ( 8 )) were prepared by the reaction of the known titanocene alkyne complexes [Cp2′Ti(η2‐Me3SiC2SiMe3)] (Cp′=Cp ( 5 ), Cp′=Cp* ( 6 )) with the corresponding amides. Complexes 1 a , 2 , 3 , 4 , 7 a , 7 b , and 8 were characterized by X‐ray crystallography. The structure and bonding of complexes 7 a and 8 were also characterized by EPR spectroscopy. 相似文献
15.
Nadine Weyer Robin Guthardt Bruno A. Correia Bicho Jan Oetzel Clemens Bruhn Ulrich Siemeling 《无机化学与普通化学杂志》2019,645(3):188-197
Three new N‐heterocyclic germylenes of the type [Fe{(η5‐C5H4)NR}2Ge] ( 1R Ge) containing particularly bulky alkyl [R = 2‐adamantyl (Ad), 1,1,2,2‐tetramethylpropyl (Pr*)] or aryl substituents [R = 2,6‐diisopropylphenyl (Dipp)] were prepared and structurally characterized, in two cases (R = Ad, Dipp), by single‐crystal X‐ray diffraction. Together with the previously described homologues with R = trimethylsilyl (TMS), tert‐butyl (tBu), and mesityl (Mes) their oxidative addition reactions with S8 and Se8 were studied, which afforded compounds of the type [ 1R Ge(μ‐E)]2 (E = S, Se). The low solubility of most of these products severely hampered their purification and characterization. Nevertheless, their structural characterization by single‐crystal X‐ray diffraction was possible in six cases (E = S, R = Ad, Pr*; E = Se, R = Ad, Pr*, Mes, Dipp). No solubility problems were encountered in oxidative addition reactions with diphenyl diselenide, affording products of the type 1R Ge(SePh2)2, whose crystal structures could be determined in four cases (R = TMS, tBu, Mes, Dipp). Short intramolecular CH ··· Se contacts compatible with hydrogen bonds were observed for [ 1Ad Ge(μ‐Se)]2, [ 1Pr* Ge(μ‐Se)]2, and 1tBu Ge(SePh2)2. 相似文献
16.
Benjamin A. Vaughan Eliza M. Arsenault Stephanie M. Chan Rory Waterman 《Journal of organometallic chemistry》2012,696(26):4327-4331
Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, (DippL)ZnEt (3, DippL = [(2,6-iPrC6H3)NC(CH3)]2CH?), a product assigned as the zinc-phosphide (DippL)ZnPHPh (6) was observed but could not be isolated as a pure compound. A new, less bulky β-diketiminate complex (TolL)ZnEt (2, TolL = [(p-CH3C6H4)NC(CH3)]2CH?) was reacted with primary phosphines to give a precipitate and the bis(β-diketiminate)zinc complex (TolL)2Zn (5), an apparent product of comproportionation. (MesAI)ZnEt (1, MesAI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized. 相似文献
17.
18.
《Journal of organometallic chemistry》2011,696(26):4327-4331
Zinc complexes of chelating monoanionic N-donors and neutral diphosphine ligands were synthesized by reaction of diethylzinc with 1,3-diketimine, diazabutadiene, and diphosphine ligand precursors. These complexes were reacted with primary phosphines in an attempt to solicit phosphine dehydrocoupling reactivity. In most cases, insoluble zinc-containing precipitates were formed and ligands were liberated. For the most sterically encumbered complex, (DippL)ZnEt (3, DippL = [(2,6-iPrC6H3)NC(CH3)]2CH−), a product assigned as the zinc-phosphide (DippL)ZnPHPh (6) was observed but could not be isolated as a pure compound. A new, less bulky β-diketiminate complex (TolL)ZnEt (2, TolL = [(p-CH3C6H4)NC(CH3)]2CH−) was reacted with primary phosphines to give a precipitate and the bis(β-diketiminate)zinc complex (TolL)2Zn (5), an apparent product of comproportionation. (MesAI)ZnEt (1, MesAI = MesNC(Me)(Et)C(Me) = NMes) and 2 were structurally characterized. 相似文献
19.
Yanfeng Jiang Olivier Blacque Dr. Thomas Fox Dr. Christian M. Frech Dr. Heinz Berke Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(7):2240-2249
The five‐coordinated ReI hydride complexes [Re(Br)(H)(NO)(PR3)2] (R=Cy 1 a , iPr 1 b ) were reacted with benzylbromide, thereby affording the 17‐electron mononuclear ReII hydride complexes [Re(Br)2(H)(NO)(PR3)2] (R=Cy 3 a , iPr 3 b ), which were characterized by EPR, cyclic voltammetry, and magnetic susceptibility measurements. In the case of dibromomethane or bromoform, the reaction of 1 afforded ReII hydrides 3 in addition to ReI carbene hydrides [Re(?CHR1)(Br)(H)(NO)(PR3)2] (R1=H 4 , Br 5 ; R=Cy a , iPr b ) in which the hydride ligand is positioned cis to the carbene ligand. For comparison, the dihydrogen ReI dibromide complexes [Re(Br)2(NO)(PR3)2(η2‐H2)] (R=Cy 2 a , iPr 2 b ) were reacted with allyl‐ or benzylbromide, thereby affording the monophosphine ReII complex salts [R3PCH2R′][Re(Br)4(NO)(PR3)] (R′=? CH?CH2 6 , Ph 7 ). The reduction of ReII complexes has also been examined. Complex 3 a or 3 b can be reduced by zinc to afford 1 a or 1 b in high yield. Under catalytic conditions, this reaction enables homocoupling of benzylbromide (turnover frequency (TOF): 3 a 150, 3 b 134 h?1) or allylbromide (TOF: 3 a 575, 3 b 562 h?1). The reaction of 6 a and 6 b with zinc in acetonitrile affords in good yields the monophosphine ReI complexes [Re(Br)2(NO)(MeCN)2(PR3)] (R=Cy 8 a , iPr 8 b ), which showed high catalytic activity toward highly selective dehydrogenative silylation of styrenes (maximum TOF of 61 h?1). Single‐electron transfer (SET) mechanisms were proposed for all these transformations. The molecular structures of 3 a , 6 a , 6 b , 7 a , 7 b , and 8 a were established by single‐crystal X‐ray diffraction studies. 相似文献
20.
Redox Behaviour of Cymantrene Fischer Carbene Complexes in Designing Organometallic Multi‐tags
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Dr. Daniela I. Bezuidenhout Belinda van der Westhuizen Pieter J. Swarts Teshica Chatturgoon Prof. Orde Q. Munro Dr. Israel Fernández Prof. Jannie C. Swarts 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(17):4974-4985
A series of Group 7 Fischer carbene complexes, [Cp(CO)2MnI=C(OEt)Ar] (Cp=cyclopentadienyl, Ar=Th=thienyl ( 1 a ), Ar=Fu=furyl ( 2 a ), Ar=Fc=ferrocenyl ( 3 a )) and biscarbene complexes, [Cp(CO)2Mn?C(OEt)?Ar′?(OEt)C?Mn(CO)2Cp] (Ar′=Th′=2,5‐thienylene ( 1 b ), Ar′=Fu′=2,5‐furylene ( 2 b ), Ar′=Fc′=1,1′‐ferrocendiyl ( 3 b )) was synthesized and characterized. Chemical oxidation of [Cp(CO)2Mn?C(OEt)Fc] ( 3 a ) and isolation of the oxidised species [3 a][PF6] possessing a MnII centre proved possible below ?30 °C in dichloromethane solution. The ESR spectrum of the transiently stable radical cation, [3 a][PF6] , confirmed the presence of a low‐spin MnII centre characterized by a rhombic g tensor (gx=1.975, gy=2.007 and gz=2.130) in frozen dichloromethane at 77 K with 55 Mn hyperfine coupling constants A1, A2 and A3 of 115, 33 and 43 G, respectively. Electrochemical studies demonstrated the influence of the Ar substituent on the oxidation potential. All complexes showed that the redox potentials of carbene double bond reduction and MnI oxidation were dependent on the type of Ar group, but only 3 b showed resolved oxidations for the two MnI centres. Surprisingly, MnI oxidation occurs at lower potentials than ferrocenyl oxidation. Density functional theory (DFT) calculations were carried out to delineate the nature of the species involved in the oxidation and reduction processes and clearly confirm that oxidation of MnI is favoured over that of ferrocene. 相似文献