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1.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(47):15304-15308
The preparation of an unprecedented GeI‐GeI bonded digermylene [K2{Ge2(μ‐κ2:η2:η4‐2,6‐(2,6‐iPr2C6H3‐N)2‐4‐CH3C5H2N)2}] in an eclipsed conformation stabilized by two bridging diamidopyridyl ligands is presented. Although it exhibits an eclipsed conformation, the Ge−Ge bond length is 2.5168(6) Å, which is shorter than those in the trans ‐bent and gauche digermylenes. In combination with two pendant amido groups, the GeI2 motif is employed as a building block to assemble the first example of octagermylene [Ge4(μ‐κ2:κ1‐2,6‐(2,6‐iPr2C6H3‐N)2‐4‐CH3C5H2N)2]2 showing a cyclic configuration and containing three distinct types of GeI−GeI bonds. 相似文献
2.
Dr. Jingjun Hao Berline Mougang‐Soumé Boris Vabre Prof. Dr. Davit Zargarian 《Angewandte Chemie (International ed. in English)》2014,53(12):3218-3222
We describe the results of a study on the stabilities of pincer‐type nickel complexes relevant to catalytic hydroalkoxylation and hydroamination of olefins, C? C and C? X couplings, and fluorination of alkyl halides. Complexes [(POCsp3OP)NiX] are stable for X=OSiMe3, OMes (Mes=1,3,5‐Me3C6H2), NPh2, and CC? H, whereas the O(tBu) and N(SiMe3)2 derivatives decompose readily. The phenylacetylide derivative transforms gradually into the zero‐valent species cis‐[{κP,κC,κC′‐(iPr2POCH2CHCH2)}Ni{η2,κC,κC′‐(iPr2P(O)CCPh)}]. Likewise, attempts to prepare [(POCsp3OP)NiF] gave instead the zwitterionic trinuclear species [{(η3‐allyl)Ni}2‐{μ,κP,κO‐(iPr2PO)4Ni}]. Characterization of these two complexes provides concrete examples of decomposition processes that can dismantle POCsp3OP‐type pincer ligands by facile C? O bond rupture. These results serve as a cautionary tale for the inherent structural fragility of pincer systems bearing phosphinite donor moieties, and provide guidelines on how to design more robust analogues. 相似文献
3.
Reaction of potassium salt of N‐aryliminopyrrole ligand [2‐(2, 6‐iPr2C6H3N=CH)–C4H3NK] ( 1 ) with samarium tris‐boro‐hydride [Sm(BH4)3(THF)3] gave a samarium ate complex [η2‐{2‐(2, 6‐iPr2C6H3N=CH)–C4H3N}3Sm(η1‐BH4){K(THF)6] ( 2 ); whereas similar treatment with erbium borohydride [Er(BH4)3(THF)3] afforded the mono(iminopyrrolyl) complex [η2‐{2‐(2, 6‐iPr2C6H3N=CH)–C4H3N}Er(η3‐BH4)2(THF)2] ( 3 ). In the solid‐state structures, the samarium complex 2 shows a rarely observed η1 and the erbium complex 3 shows a usual η3 coordination mode of the borohydrido ligand. 相似文献
4.
《Journal of Coordination Chemistry》2012,65(20):3718-3726
We report the synthesis and structural determination of three uranium(IV) complexes bearing two, four, and six salicylaldiminate ligands. Reaction of UI4(1,4-dioxane)2 with two, four, and six equivalents of K[OC6H4C(H)=N(2,6-iPr2C6H3)], 1, yielded [(2,6-iPr2C6H3)N=C(H)C6H4O-κ2(O,N)]2UI2(NCCH3), 2, [(2,6-iPr2C6H3)N=C(H)C6H4O-κ1(O)]2[(2,6-iPr2C6H3)N=C(H)C6H4O-κ2(O,N)]2U(THF), 3, and {[2,6-iPr2C6H3)N=C(H)C6H4O-κ1(O)]6U}2?, 4. While 2 shows normal κ2-coordination through both oxygen and nitrogen donors, 3 has two salicylaldiminate ligands bound only through oxygen and 4 has all six ligands bound only through oxygen. This is an exceedingly rare example of a chelating ligand not completing its chelation in f-element chemistry. In addition, 4 is the first report of a homoleptic octahedral actinide complex with a Schiff base ligand. 相似文献
5.
Christoph Helling George E. Cutsail Hanns Weinert Christoph Wlper Stephan Schulz 《Angewandte Chemie (International ed. in English)》2020,59(19):7561-7568
We report on the structures of three unprecedented heteroleptic Sb‐centered radicals [L(Cl)Ga](R)Sb. ( 2‐R , R=B[N(Dip)CH]2 2‐B , 2,6‐Mes2C6H3 2‐C , N(SiMe3)Dip 2‐N ) stabilized by one electropositive metal fragment [L(Cl)Ga] (L=HC[C(Me)N(Dip)]2, Dip=2,6‐i‐Pr2C6H3) and one bulky B‐ ( 2‐B ), C‐ ( 2‐C ), or N‐based ( 2‐N ) substituent. Compounds 2‐R are predominantly metal‐centered radicals. Their electronic properties are largely influenced by the electronic nature of the ligands R, and significant delocalization of unpaired‐spin density onto the ligands was observed in 2‐B and 2‐N . Cyclic voltammetry (CV) studies showed that 2‐B undergoes a quasi‐reversible one‐electron reduction, which was confirmed by the synthesis of [K([2.2.2]crypt)][L(Cl)GaSbB[N(Dip)CH]2] ([K([2.2.2]crypt)][ 2‐B ]) containing the stibanyl anion [ 2‐B ]?, which was shown to possess significant Sb?B multiple‐bonding character. 相似文献
6.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(48):15629-15633
Herein we report the employment of the quintuply bonded dichromium amidinates [Cr{κ2‐HC(N‐2,6‐iPr2C6H3)(N‐2,6‐R2C6H3)}]2 (R=iPr ( 1 ), Me ( 7 )) as catalysts to mediate the [2+2+2] cyclotrimerization of terminal alkynes giving 1,3,5‐trisubstituted benzenes. During the catalysis, the ultrashort Cr−Cr quintuple bond underwent reversible cleavage/formation, corroborated by the characterization of two inverted arene sandwich dichromium complexes (μ‐η6:η6‐1,3,5‐(Me3Si)3C6H3)[Cr{κ2‐HC(N ‐2,6‐iPr2C6H3)(N ‐2,6‐R2C6H3)}]2 (R=iPr ( 5 ), Me ( 8 )). In the presence of σ donors, such as THF and 2,4,6‐Me3C6H2CN, the bridging arene 1,3,5‐(Me3Si)3C6H3 in 5 and 8 was extruded and 1 and 7 were regenerated. Theoretical calculations were employed to disclose the reaction pathways of these highly regioselective [2+2+2] cylcotrimerization reactions of terminal alkynes. 相似文献
7.
A Family of Multiply Bonded Dimolybdenum Boraamidinates with the Formal Mo−Mo Bond Orders of 3, 4, 4.5, and 5
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Dr. Duan‐Yen Lu Ting‐Shen Kuo Prof. Dr. Yi‐Chou Tsai 《Angewandte Chemie (International ed. in English)》2016,55(38):11614-11618
A boraamidinato ligand [PhB(N‐2,6‐iPr2C6H3)2]2? was employed to stabilize a new family of multiply bonded dimolybdenum complexes [MoCl(μ‐κ2‐PhB(N‐2,6‐iPr2C6H3)2)]2 ( 4 ) and [Mo(μ‐κ2‐PhB(N‐2,6‐iPr2C6H3)2)]2n? (n=0 ( 5 ), 1 ( 6 ), 2 ( 7 )), with the respective formal Mo?Mo bond orders of 3, 4, 4.5, and 5. Each metal center in 5 – 7 is two‐coordinate with respect to the ligands. Of particular interest is the quadruply bonded dimolybdenum complex 5 , featuring an unprecedented angular conformation. The bent Mo2N4 core of 5 distorts toward planarity upon reduction. As a result, compound 7 features a planar Mo2N4 core, while that of 6 is still bent but less significantly than that of 5 . Additionally, the Mo?Mo bond lengths of 4 – 7 systematically decrease as the valency of the central Mo2 units decreases. Complex 7 features the shortest Mo?Mo bond length (2.0106(5) Å) yet reported. 相似文献
8.
Dapeng Zhao Dr. Wei Gao Dr. Ying Mu Prof. Ling Ye 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(14):4394-4401
A series of new titanium(IV) complexes with o‐metalated arylimine and/or cis‐9,10‐dihydrophenanthrenediamide ligands, [o‐C6H4(CH?NR)TiCl3] (R=2,6‐iPr2C6H3 ( 3 a ), 2,6‐Me2C6H3 ( 3 b ), tBu ( 3 c )), [cis‐9,10‐PhenH2(NR)2TiCl2] (PhenH2=9,10‐dihydrophenanthrene; R=2,6‐iPr2C6H3 ( 4 a ), 2,6‐Me2C6H3 ( 4 b ), tBu ( 4 c )), [{cis‐9,10‐PhenH2(NR)2}{o‐C6H4(HC?NR)}TiCl] (R=2,6‐iPr2C6H3 ( 5 a ), 2,6‐Me2C6H3 ( 5 b ), tBu ( 5 c )), have been synthesised from the reactions of TiCl4 with o‐C6H4(CH?NR)Li (R=2,6‐iPr2C6H3, 2,6‐Me2C6H3, tBu). Complexes 4 and 5 were formed unexpectedly from the reactions of TiCl4 with two or three equivalents of the corresponding o‐C6H4(CH?NR)Li followed by sequential intramolecular C? C bond‐forming reductive elimination and oxidative coupling reactions. Attempts to isolate the intermediates, [{o‐C6H4(CH?NR)}2TiCl2] ( 2 ), were unsuccessful. All complexes were characterised by 1H and 13C NMR spectroscopy, and the molecular structures of 3 a , 4 a – c , 5 a , and 5 c were determined by X‐ray crystallography. 相似文献
9.
Bis(β‐diketiminato) lanthanide amides: synthesis,structure and catalysis for the polymerization of l‐lactide and ε‐caprolactone
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Yu Zheng Rui Jiao Xiao‐dong Shen Ming‐qiang Xue Ying‐ming Yao Yong Zhang Qi Shen 《应用有机金属化学》2014,28(6):461-470
Treatment of the chlorides (L2,6‐iPr2Ph)2LnCl (L2,6‐iPr2Ph = [(2,6‐iPr2C6H3)NC(Me)CHC(Me)N(C6H5)]?) with 1 equiv. of NaNH(2,6‐iPr2C6H3) afforded the monoamides (L2,6‐iPr2Ph)2LnNH(2,6‐iPr2C6H3) (Ln = Y ( 1 ), Yb ( 2 )) in good yields. Anhydrous LnCl3 reacted with 2 equiv. of NaL2,6‐iPr2Ph in THF, followed by treatment with 1 equiv. of NaNH(2,6‐iPr2C6H3), giving the analogues (L2,6‐iPr2Ph)2LnNH(2,6‐iPr2C6H3) (Ln = Sm ( 3 ), Nd ( 4 )). Two monoamido complexes stabilized by two L2‐Me ligands, (L2‐Me)2LnNH(2,6‐iPr2C6H3) (L2‐Me = [N(2‐MeC6H4)C(Me)]2CH)?; Ln = Y ( 5 ), Yb ( 6 )), were also synthesized by the latter route. Complexes 1 , 2 , 3 , 4 , 5 , 6 were fully characterized, including X‐ray crystal structure analyses. Complexes 1 , 2 , 3 , 4 , 5 , 6 are isostructural. The central metal in each complex is ligated by two β‐diketiminato ligands and one amido group in a distorted trigonal bipyramid. All the complexes were found to be highly active in the ring‐opening polymerization of L‐lactide (L‐LA) and ε‐caprolactone (ε‐CL) to give polymers with relatively narrow molar mass distributions. The activity depends on both the central metal and the ligand (Yb < Y < Sm ≈ Nd and L2‐Me < L2,6‐iPr2Ph). Remarkably, the binary 3/benzyl alcohol (BnOH) system exhibited a striking ‘immortal’ nature and proved able to quantitatively convert 5000 equiv. of L‐LA with up to 100 equiv. of BnOH per metal initiator. All the resulting PLAs showed monomodal, narrow distributions (Mw/Mn = 1.06 ? 1.08), with molar mass (Mn) decreasing proportionally with an increasing amount of BnOH. The binary 4/BnOH system also exhibited an ‘immortal’ nature in the polymerization of ε‐CL in toluene. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
10.
Dr. Beatriz Eguillor Prof. Dr. Miguel A. Esteruelas Virginia Lezáun Dr. Montserrat Oliván Dr. Enrique Oñate Dr. Jui‐Yi Tsai Dr. Chuanjun Xia 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(27):9106-9110
A MHC6 complex of a platinum group metal with a capped octahedral arrangement of donor atoms around the metal center has been characterized. This osmium compound OsH{κ2‐C,C‐(PhBIm‐C6H4)}3, which reacts with HBF4 to afford the 14 e? species [Os{κ2‐C,C‐(PhBIm‐C6H4)}(Ph2BIm)2]BF4 stabilized by two agostic interactions, has been obtained by reaction of OsH6(PiPr3)2 with N,N′‐diphenylbenzimidazolium chloride ([Ph2BImH]Cl) in the presence of NEt3. Its formation takes place through the C,C,C‐pincer compound OsH2{κ3‐C,C,C‐(C6H4‐BIm‐C6H4)}(PiPr3)2, the dihydrogen derivative OsCl{κ2‐C,C‐(PhBIm‐C6H4)}(η2‐H2)(PiPr3)2, and the five‐coordinate osmium(II) species OsCl{κ2‐C,C‐(PhBIm‐C6H4)}(PiPr3)2. 相似文献
11.
Dr. Shihui Li Dr. Meiyan Wang Bo Liu Lei Li Prof. Jianhua Cheng Dr. Chunji Wu Dr. Dongtao Liu Prof. Dr. Jingyao Liu Prof. Dr. Dongmei Cui 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15493-15498
The first four‐coordinate methanediide/alkyl lutetium complex (BODDI)Lu2(CH2SiMe3)2(μ2‐CHSiMe3)(THF)2 (BODDI=ArNC(Me)CHCOCHC(Me)NAr, Ar=2,6‐iPr2C6H3) ( 1 ) was synthesized by a thermolysis methodology through α‐H abstraction from a Lu–CH2SiMe3 group. Complex 1 reacted with equimolar 2,6‐iPrC6H3NH2 and Ph2C?O to give the corresponding lutetium bridging imido and oxo complexes (BODDI)Lu2(CH2SiMe3)2(μ2‐N‐2,6‐iPr2C6H3)(THF)2 ( 2 ) and (BODDI)Lu2(CH2SiMe3)2(μ2‐O)(THF)2 ( 3 ). Treatment of 3 with Ph2C?O (4 equiv) caused a rare insertion of Lu–μ2‐O bond into the C?O group to afford a diphenylmethyl diolate complex 4 . Reaction of 1 with PhN=C?O (2 equiv) led to the migration of SiMe3 to the amido nitrogen atom to give complex (BODDI)Lu2(CH2SiMe3)2‐μ‐{PhNC(O)CHC(O)NPh(SiMe3)‐κ3N,O,O}(THF) ( 5 ). Reaction of 1 with tBuN?C formed an unprecedented product (BODDI)Lu2(CH2SiMe3){μ2‐[η2:η2‐tBuNC(=CH2)SiMe2CHC?NtBu‐κ1N]}(tBuN?C)2 ( 6 ) through a cascade reaction of N?C bond insertion, sequential cyclometalative γ‐(sp3)‐H activation, C?C bond formation, and rearrangement of the newly formed carbene intermediate. The possible mechanistic pathways between 1 , PhN?C?O, and tBuN?C were elucidated by DFT calculations. 相似文献
12.
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
13.
Experimental and Computational Studies on the Reactivity of a Terminal Thorium Imidometallocene towards Organic Azides and Diazoalkanes
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Dr. Wenshan Ren Enwei Zhou Bo Fang Dr. Guohua Hou Prof. Guofu Zi Prof. De‐Cai Fang Dr. Marc D. Walter 《Angewandte Chemie (International ed. in English)》2014,53(42):11310-11314
The reaction of the base‐free terminal thorium imido complex [{η5‐1,2,4‐(Me3C)3C5H2}2Th?N(p‐tolyl)] ( 1 ) with p‐azidotoluene yielded irreversibly the tetraazametallacyclopentene [{η5‐1,2,4‐(Me3C)3C5H2}2Th{N(p‐tolyl)N?N? N(p‐tolyl)}] ( 2 ), whereas the bridging imido complex [{[η5‐1,2,4‐(Me3C)3C5H2]Th(N3)2}2{μ‐N(p‐tolyl)}2][(n‐C4H9)4N]2 ( 3 ) was isolated from the reaction of 1 with [(n‐C4H9)4N]N3. Unexpectedly, upon the treatment of 1 with 9‐diazofluorene, the NN bond was cleaved, an N atom was transferred, and the η2‐diazenido iminato complex [{η5‐1,2,4‐(Me3C)3C5H2}2Th{η2‐[N?N(p‐tolyl)]}{N?(9‐C13H8)}] ( 4 ) was formed. In contrast, the reaction of 1 with Me3SiCHN2 gave the nitrilimido complex [{η5‐1,2,4‐(Me3C)3C5H2}2Th{NH(p‐tolyl)}{N2CSiMe3}] ( 5 ), which slowly converted into [{η5‐1,2,4‐(Me3C)3C5H2}{η5:κ‐N‐1,2‐(Me3C)2‐4‐CMe2(CH2NN?CHSiMe3)C5H2}Th{NH(p‐tolyl)}] ( 6 ) by intramolecular C? H bond activation. The experimental results are complemented by density functional theory (DFT) studies. 相似文献
14.
Prof. Carl Redshaw Mark Walton Dr. Lucy Clowes Dr. David L. Hughes Dr. Anna‐Marie Fuller Dr. Yimin Chao Dr. Alex Walton Dr. Victor Sumerin Dr. Pertti Elo Dr. Igor Soshnikov Dr. Weizhen Zhao Prof. Wen‐Hua Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(27):8884-8899
The reactions of MCl5 or MOCl3 with imidazole‐based pro‐ligand L1H, 3,5‐tBu2‐2‐OH‐C6H2‐(4,5‐Ph2‐1H‐)imidazole, or oxazole‐based ligand L2H, 3,5‐tBu2‐2‐OH‐C6H2(1H‐phenanthro[9,10‐d])oxazole, following work‐up, afforded octahedral complexes [MX(L1, 2)], where MX=NbCl4 (L1, 1 a ; L2, 2 a ), [NbOCl2(NCMe)] (L1, 1 b ; L2, 2 b ), TaCl4 (L1, 1 c ; L2, 2 c ), or [TaOCl2(NCMe)] (L1, 1 d ). The treatment of α‐diimine ligand L3, (2,6‐iPr2C6H3N?CH)2, with [MCl4(thf)2] (M=Nb, Ta) afforded [MCl4(L3)] (M=Nb, 3 a ; Ta, 3 b ). The reaction of [MCl3(dme)] (dme=1,2‐dimethoxyethane; M=Nb, Ta) with bis(imino)pyridine ligand L4, 2,6‐[2,6‐iPr2C6H3N?(Me)C]2C5H3N, afforded known complexes of the type [MCl3(L4)] (M=Nb, 4 a ; Ta, 4 b ), whereas the reaction of 2‐acetyl‐6‐iminopyridine ligand L5, 2‐[2,6‐iPr2C6H3N?(Me)C]‐6‐Ac‐C5H3N, with the niobium precursor afforded the coupled product [({2‐Ac‐6‐(2,6‐iPr2C6H3N?(Me)C)C5H3N}NbOCl2)2] ( 5 ). The reaction of MCl5 with Schiff‐base pro‐ligands L6H–L10H, 3,5‐(R1)2‐2‐OH‐C6H2CH?N(2‐OR2‐C6H4), (L6H: R1=tBu, R2=Ph; L7H: R1=tBu, R2=Me; L8H: R1=Cl, R2=Ph; L9H: R1=Cl, R2=Me; L10H: R1=Cl, R2=CF3) afforded [MCl4(L6–10)] complexes (M=Nb, 6 a – 10 a ; M=Ta, 6 b – 9 b ). In the case of compound 8 b , the corresponding zwitterion was also synthesised, namely [Ta?Cl5(L8H)+] ? MeCN ( 8 c ). Unexpectedly, the reaction of L7H with TaCl5 at reflux in toluene led to the removal of the methyl group and the formation of trichloride 7 c [TaCl3(L7‐Me)]; conducting the reaction at room temperature led to the formation of the expected methoxy compound ( 7 b ). Upon activation with methylaluminoxane (MAO), these complexes displayed poor activities for the homogeneous polymerisation of ethylene. However, the use of chloroalkylaluminium reagents, such as dimethylaluminium chloride (DMAC) and methylaluminium dichloride (MADC), as co‐catalysts in the presence of the reactivator ethyl trichloroacetate (ETA) generated thermally stable catalysts with, in the case of niobium, catalytic activities that were two orders of magnitude higher than those previously observed. The effects of steric hindrance and electronic configuration on the polymerisation activity of these tantalum and niobium pre‐catalysts were investigated. Spectroscopic studies (1H NMR, 13C NMR and 1H? 1H and 1H? 13C correlations) on the reactions of compounds 4 a / 4 b with either MAO(50) or AlMe3/[CPh3]+[B(C6F5)4]? were consistent with the formation of a diamagnetic cation of the form [L4AlMe2]+ (MAO(50) is the product of the vacuum distillation of commercial MAO at +50 °C and contains only 1 mol % of Al in the form of free AlMe3). In the presence of MAO, this cationic aluminium complex was not capable of initiating the ROMP (ring opening metathesis polymerisation) of norbornene, whereas the 4 a / 4 b systems with MAO(50) were active. A parallel pressure reactor (PPR)‐based homogeneous polymerisation screening by using pre‐catalysts 1 b , 1 c , 2 a , 3 a and 6 a , in combination with MAO, revealed only moderate‐to‐good activities for the homo‐polymerisation of ethylene and the co‐polymerisation of ethylene/1‐hexene. The molecular structures are reported for complexes 1 a – 1 c , 2 b , 5 , 6 a , 6 b, 7 a, 8 a and 8 c . 相似文献
15.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(6):673-682
The reactions of K[(2,6‐iPr2C6H3‐O)2POO] either with LaCl3(H2O)7 or with Nd(NO3)3(H2O)6 in a 3:1 molar ratio, followed by vacuum drying and recrystallization from alkanes, have led to the formation of diaquapentakis[bis(2,6‐diisopropylphenyl) phosphato]‐μ‐hydroxido‐dilanthanum hexane disolvate, [La2(C24H34O4P)5(OH)(H2O)2]·2C6H14, ( 1 )·2(hexane), and tetraaquatetrakis[bis(2,6‐diisopropylphenyl) phosphato]‐μ‐hydroxido‐dineodymium bis(2,6‐diisopropylphenyl) phosphate heptane disolvate, [Nd2(C24H34O4P)4(OH)(H2O)4]·2C6H14, ( 2 )·2(heptane). The compounds crystalize in the P21/n and P space groups, respectively. The diaryl‐substituted organophosphate ligand exhibits three different coordination modes, viz. κ2O,O′‐terminal [in ( 1 ) and ( 2 )], κO‐terminal [in ( 1 )] and μ2‐κ1O:κ1O′‐bridging [in ( 1 ) and ( 2 )]. Binuclear structures ( 1 ) and ( 2 ) are similar and have the same unique Ln2(μ‐OH)(μ‐OPO)2 core. The structure of ( 2 ) consists of an [Nd2{(2,6‐iPr2C6H3‐O)2POO}4(OH)(H2O)4]+ cation and a [(2,6‐iPr2C6H3‐O)2POO]− anion, which are bound via four intermolecular O—H…O hydrogen bonds. The molecular structure of ( 1 ) displays two O—H…O hydrogen bonds between OH/H2O ligands and a κ1O‐terminal organophosphate ligand, which resembles, to some extent, the `free' [(2,6‐iPr2C6H3‐O)2POO]− anion in ( 2 ). NMR studies have shown that the formation of ( 1 ) undoubtedly occurs due to intramolecular hydrolysis during vacuum drying of the aqueous La tris(phosphate) complex. Catalytic experiments have demonstrated that the presence of the coordinated hydroxide anion and water molecules in precatalyst ( 2 ) substantially lowered the catalytic activity of the system prepared from ( 2 ) in butadiene and isoprene polymerization compared to the catalytic system based on the neodymium tris[bis(2,6‐diisopropylphenyl) phosphate] complex, which contains neither OH nor H2O ligands. 相似文献
16.
Structural Diversity in Alkali Metal and Alkali Metal Magnesiate Chemistry of the Bulky 2,6‐Diisopropyl‐N‐(trimethylsilyl)anilino Ligand
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Dr. M. Ángeles Fuentes Andoni Zabala Dr. Alan R. Kennedy Prof. Robert E. Mulvey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):14968-14978
Bulky amido ligands are precious in s‐block chemistry, since they can implant complementary strong basic and weak nucleophilic properties within compounds. Recent work has shown the pivotal importance of the base structure with enhancement of basicity and extraordinary regioselectivities possible for cyclic alkali metal magnesiates containing mixed n‐butyl/amido ligand sets. This work advances alkali metal and alkali metal magnesiate chemistry of the bulky arylsilyl amido ligand [N(SiMe3)(Dipp)]? (Dipp=2,6‐iPr2‐C6H3). Infinite chain structures of the parent sodium and potassium amides are disclosed, adding to the few known crystallographically characterised unsolvated s‐block metal amides. Solvation by N,N,N′,N′′,N′′‐pentamethyldiethylenetriamine (PMDETA) or N,N,N′,N′‐tetramethylethylenediamine (TMEDA) gives molecular variants of the lithium and sodium amides; whereas for potassium, PMDETA gives a molecular structure, TMEDA affords a novel, hemi‐solvated infinite chain. Crystal structures of the first magnesiate examples of this amide in [MMg{N(SiMe3)(Dipp)}2(μ‐nBu)]∞ (M=Na or K) are also revealed, though these breakdown to their homometallic components in donor solvents as revealed through NMR and DOSY studies. 相似文献
17.
Terry Chu Lee Belding Prof. Dr. Art van der Est Prof. Dr. Travis Dudding Dr. Ilia Korobkov Dr. Georgii I. Nikonov 《Angewandte Chemie (International ed. in English)》2014,53(10):2711-2715
Reduction of the cationic GeII complex [dimpyrGeCl][GeCl3] (dimpyr=2,6‐(ArN=CMe)2NC5H3, Ar=2,6‐iPr2C6H3) with potassium graphite in benzene affords an air sensitive, dark green compound of Ge0, [dimpyrGe], which is stabilized by a bis(imino)pyridine platform. This compound is the first example of a complex of a zero‐valent Group 14 element that does not contain a carbene or carbenoid ligand. This species has a singlet ground state. DFT studies revealed partial delocalization of one of the Ge lone pairs over the π*(C?N) orbitals of the imines. This delocalization results in a partial multiple‐bond character between the Ge atom and imine nitrogen atoms, a fact supported by the X‐ray crystallography and IR spectroscopy data. 相似文献
18.
From Dibismuthenes to Three‐ and Two‐Coordinated Bismuthinidenes by Fine Ligand Tuning: Evidence for Aromatic BiC3N Rings through a Combined Experimental and Theoretical Study
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Iva Vránová Dr. Mercedes Alonso Dr. Rabindranath Lo Dr. Robert Sedlák Dr. Roman Jambor Prof. Aleš Růžička Prof. Frank De Proft Prof. Pavel Hobza Dr. Libor Dostál 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16917-16928
The reduction of N,C,N‐chelated bismuth chlorides [C6H3‐2,6‐(CH?NR)2]BiCl2 [where R=tBu ( 1 ), 2′,6′‐Me2C6H3 ( 2 ), or 4′‐Me2NC6H4 ( 3 )] or N,C‐chelated analogues [C6H2‐2‐(CH?N‐2′,6′‐iPr2C6H3)‐4,6‐(tBu)2]BiCl2 ( 4 ) and [C6H2‐2‐(CH2NEt2)‐4,6‐(tBu)2]BiCl2 ( 5 ) is reported. Reduction of compounds 1 – 3 gave monomeric N,C,N‐chelated bismuthinidenes [C6H3‐2,6‐(CH?NR)2]Bi [where R=tBu ( 6 ), 2′,6′‐Me2C6H3 ( 7 ) or 4′‐Me2NC6H4 ( 8 )]. Similarly, the reduction of 4 led to the isolation of the compound [C6H2‐2‐(CH?N‐2′,6′‐iPr2C6H3)‐4,6‐(tBu)2]Bi ( 9 ) as an unprecedented two‐coordinated bismuthinidene that has been structurally characterized. In contrast, the dibismuthene {[C6H2‐2‐(CH2NEt2)‐4,6‐(tBu)2]Bi}2 ( 10 ) was obtained by the reduction of 5 . Compounds 6 – 10 were characterized by using 1H and 13C NMR spectroscopy and their structures, except for 7 , were determined with the help of single‐crystal X‐ray diffraction analysis. It is clear that the structure of the reduced products (bismuthinidene versus dibismuthene) is ligand‐dependent and particularly influenced by the strength of the N→Bi intramolecular interaction(s). Therefore, a theoretical survey describing the bonding situation in the studied compounds and related bismuth(I) systems is included. Importantly, we found that the C3NBi chelating ring in the two‐coordinated bismuthinidene 9 exhibits significant aromatic character by delocalization of the bismuth lone pair. 相似文献
19.
Stefan Sander Dr. Robert Müller Dr. Mike Ahrens Prof. Dr. Martin Kaupp Prof. Dr. Thomas Braun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(57):14287-14298
The reaction of [PtCl2(COD)] (COD=1,5-cyclooctadiene) with diisopropyl-2-(3-methyl)indolylphosphine (iPr2P(C9H8N)) led to the formation of the platinum(ii ) chlorido complexes, cis-[PtCl2{iPr2P(C9H8N)}2] ( 1 ) and trans-[PtCl2{iPr2P(C9H8N)}2] ( 2 ). The cis-complex 1 reacted with NEt3 yielding the complex cis-[PtCl{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}] ( 3 ) bearing a cyclometalated κ2-(P,N)-phosphine ligand, while the isomer 2 with a trans-configuration did not show any reactivity towards NEt3. Treatment of 1 or 3 with (CH3)4NF (TMAF) resulted in the formation of the twofold cyclometalated complex cis-[Pt{κ2-(P,N)-iPr2P(C9H7N)}2] ( 4 ). The molecular structures of the complexes 1–4 were determined by single-crystal X-ray diffraction. The fluorido complex cis-[PtF{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}] ⋅ (HF)4 ( 5 ⋅ (HF)4) was formed when complex 4 was treated with different hydrogen fluoride sources. The Pt(ii ) fluorido complex 5 ⋅ (HF)4 exhibits intramolecular hydrogen bonding in its outer coordination sphere between the fluorido ligand and the NH group of the 3-methylindolyl moiety. In contrast to its chlorido analogue 3 , complex 5 ⋅ (HF)4 reacted with CO or the ynamide 1-(2-phenylethynyl)-2-pyrrolidinone to yield the complexes trans-[Pt(CO){κ2-(P,C)-iPr2P(C9H7NCO)}{iPr2P(C9H8N)}][F(HF)4] ( 7 ) and a complex, which we suggest to be cis-[Pt{C=C(Ph)OCN(C3H6)}{κ2-(P,N)-iPr2P(C9H7N)}{iPr2P(C9H8N)}][F(HF)4] ( 9 ), respectively. The structure of 9 was assigned on the basis of DFT calculations as well as NMR and IR data. Hydrogen bonding of HF and NH to fluoride was proven to be crucial for the existence of 7 and 9 . 相似文献
20.
Experimental and Theoretical Studies on Arene‐Bridged Metal–Metal‐Bonded Dimolybdenum Complexes
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Dr. Mario Carrasco Natalia Curado Dr. Eleuterio Álvarez Dr. Celia Maya Dr. Riccardo Peloso Prof. Dr. Manuel L. Poveda Dr. Amor Rodríguez Prof. Dr. Eliseo Ruiz Prof. Dr. Santiago Álvarez Prof. Dr. Ernesto Carmona 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(20):6092-6102
The bis(hydride) dimolybdenum complex, [Mo2(H)2{HC(N‐2,6‐iPr2C6H3)2}2(thf)2], 2 , which possesses a quadruply bonded Mo2II core, undergoes light‐induced (365 nm) reductive elimination of H2 and arene coordination in benzene and toluene solutions, with formation of the MoI2 complexes [Mo2{HC(N‐2,6‐iPr2C6H3)2}2(arene)], 3?C6H6 and 3?C6H5Me , respectively. The analogous C6H5OMe, p‐C6H4Me2, C6H5F, and p‐C6H4F2 derivatives have also been prepared by thermal or photochemical methods, which nevertheless employ different Mo2 complex precursors. X‐ray crystallography and solution NMR studies demonstrate that the molecule of the arene bridges the molybdenum atoms of the MoI2 core, coordinating to each in an η2 fashion. In solution, the arene rotates fast on the NMR timescale around the Mo2‐arene axis. For the substituted aromatic hydrocarbons, the NMR data are consistent with the existence of a major rotamer in which the metal atoms are coordinated to the more electron‐rich C?C bonds. 相似文献