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1.
Reactivity of Liquid Ammonia Solutions of the Zintl Phase K12Sn17 towards Mesitylcopper(I) and Phosphinegold(I) Chloride
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Dr. Christian B. Benda Dr. Markus Waibel Dr. Tobias Köchner Prof. Dr. Thomas F. Fässler 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16738-16746
To gain more insight into the reactivity of intermetalloid clusters, the reactivity of the Zintl phase K12Sn17, which contains [Sn4]4? and [Sn9]4? cluster anions, was investigated. The reaction of K12Sn17 with gold(I) phosphine chloride yielded K7[(η2‐Sn4)Au(η2‐Sn4)](NH3)16 ( 1 ) and K17[(η2‐Sn4)Au(η2‐Sn4)]2(NH2)3(NH3)52 ( 2 ), which both contain the anion [(Sn4)Au(Sn4)]7? ( 1 a ) that consists of two [Sn4]4? tetrahedra linked through a central gold atom. Anion 1 a represents the first binary Au?Sn polyanion. From this reaction, the solvate structure [K([2.2.2]crypt)]3K[Sn9](NH3)18 ( 3 ; [2.2.2]crypt=4,7,13,16,21,24‐hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacosane) was also obtained. In the analogous reaction of mesitylcopper with K12Sn17 in the presence of [18]crown‐6 in liquid ammonia, crystals of the composition [K([18]crown‐6)]2[K([18]crown‐6)(MesH)(NH3)][Cu@Sn9](thf) ( 4 ) were isolated ([18]crown‐6=1,4,7,10,13,16‐hexaoxacyclooctadiene, MesH=mesitylene, thf=tetrahydrofuran) and featured a [Cu@Sn9]3? cluster. A similar reaction with [2.2.2]crypt as a sequestering agent led to the formation of crystals of [K[2.2.2]crypt][MesCuMes] ( 5 ). The cocrystallization of mesitylene in 4 and the presence of [MesCuMes]? ( 5 a ) in 5 provides strong evidence that the migration of a bare Cu atom into an Sn9 anion takes place through the release of a Mes? anion from mesitylcopper, which either migrates to another mesitylcopper to form 5 a or is subsequently protonated to give MesH. 相似文献
2.
Alberto R. Dias Ana M. Martins João F. da Silva Sandra S. Rodrigues 《Journal of organometallic chemistry》2004,689(1):203-213
The synthesis of [TiInd(NCtBu2)Cl2] and the applications of [TiCp′(NCtBu2)Cl2] (Cp′=Ind, Cp*, Cp) as ethylene and propylene homopolymerisation catalysts, as well as its behaviour as catalysts of ethylene and 10-undecen-1-ol copolymerisation are described. The optimisation of the catalytic reactions showed that all compounds are very active homopolymerisation catalysts, particularly [TiInd(NCtBu2)Cl2] that gives 123.37 × 106 g/(molTi [E] h) and 50.77 × 106 g/(molTi [P] h) of linear polyethylene and atatic polypropylene, respectively. The less active homopolymerisation catalyst, [TiCp(NCtBu2)Cl2], is the most effective ethylene/10-undecen-1-ol copolymerisation catalyst, leading to the highest degree of polar monomer incorporation. The polymers obtained were characterised by NMR and DSC. The molecular structures of [TiCp′(NCtBu2)Cl2] (Cp′=Ind, Cp*) were determined by X-ray diffraction studies. 相似文献
3.
Andreas Sofetis Fotini Fotopoulou Catherine P. Raptopoulou Theodoros F. Zafiropoulos Spyros P. Perlepes Nikolaos Klouras 《Polyhedron》2009
The reaction of [TiIV(Cp)2Cl2] (Cp− = η5-C5H5−) and 2,6-bis(3,5-dimethylpyrazolyl-1-yl)pyridine (bdmpp) in Me2CO has afforded complex [TiIVCl2(O2)(bdmpp)] (1). The complex can also be prepared from the 1:1:1 [Ti(Cp)2Cl2]/bdmpp/H2O2 reaction mixture in various solvents. Single-crystal, X-ray crystallography has revealed that the TiIV center is in a distorted pentagonal bipyramidal environment in both of the two, crystallographically independent molecules that are present in the asymmetric unit; the equatorial positions are occupied by the two O atoms of the side-on (η2) O22− group and the three N-atoms of the tridentate chelate, while the two chloro ligands are on the axial positions. IR, Raman, electronic and 1H NMR data are discussed in terms of the known structure and the coordination modes of the peroxo and bdmpp ligands. 相似文献
4.
Niobium and Tantalum Complexes with P2 and P4 Ligands The photolysis of [Cp″Ta(CO)4] 1 (Cp″ = C5H3tBu2?1,3) and P4 affords Cp″(CO)2Ta(η4?P4) 2 , [{Cp″(CO)Ta}2(m??η2:2?P2)2] 3 and [Cp3″(CO)3Ta3(P2)2] 4 . In a photochemical reaction 2 and [Cp*Nb(CO)4] 5 form [{Cp*(CO)Nb}{Cp″(CO)Ta}(m??η2:2?P2)2] 6 and [{Cp*(CO)2Nb} {Cp*Nb}{Cp″(CO)Ta}(m?3?η2:1:1?P2)2] 7 , a compound with the novel m?3?η2:2:1?P2-coordination mode. The reaction of 2 and [Cp*Co(C2H4)2] 8 leads to [{Cp*Co} {Cp″(CO)Ta}(m??η2:2?P2)2] 9 , a heteronuclear complex with an ?early”? and a ?late”? transition metal. Complexes 2, 3, 7 and 9 have been further characterized by X-ray structure analyses. 相似文献
5.
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
6.
A series of binuclear complexes [{Cp*Ir(OOCCH2COO)}2(pyrazine)] ( 1 b ), [{Cp*Ir(OOCCH2COO)}2(bpy)] ( 2 b ; bpy=4,4′‐bipyridine), [{Cp*Ir(OOCCH2COO)}2(bpe)] ( 3 b ; bpe=trans‐1,2‐bis(4‐pyridyl)ethylene) and tetranuclear metallamacrocycles [{(Cp*Ir)2(OOC‐C?C‐COO)(pyrazine)}2] ( 1 c ), [{(Cp*Ir)2(OOC‐C?C‐COO)(bpy)}2] ( 2 c ), [{(Cp*Ir)2(OOC‐C?C‐COO)(bpe)}2] ( 3 c ), and [{(Cp*Ir)2[OOC(H3C6)‐N?N‐(C6H3)COO](pyrazine)}2] ( 1 d ), [{(Cp*Ir)2[OOC(H3C6)‐N?N‐(C6H3)COO](bpy)}2] ( 2 d ), [{(Cp*Ir)2[OOC(H3C6)‐N?N‐(C6H3)COO](bpe)}2] ( 3 d ) were formed by reactions of 1 a – 3 a {[(Cp*Ir)2(pyrazine)Cl2] ( 1 a ), [(Cp*Ir)2(bpy)Cl2] ( 2 a ), and [(Cp*Ir)2(bpe)Cl2] ( 3 a )} with malonic acid, fumaric acid, or H2ADB (azobenzene‐4,4′‐chcarboxylic acid), respectively, under mild conditions. The metallamacrocycles were directly self‐assembled by activation of C? H bonds from dicarboxylic acids. Interestingly, after exposure to UV/Vis light, 3 c was converted to [2+2] cycloaddition complex 4 . The molecular structures of 2 b , 1 c , 1 d , and 4 were characterized by single‐crystal x‐ray crystallography. Nanosized tubular channels, which may play important roles for their stability, were also observed in 1 c , 1 d , and 4 . All complexes were well characterized by 1H NMR and IR spectroscopy, as well as elemental analysis. 相似文献
7.
Dr. Dirk Hollmann Dr. Kathleen Grabow Dr. Haijun Jiao Dr. Monty Kessler Dr. Anke Spannenberg Dr. Torsten Beweries Dr. Ursula Bentrup Prof. Angelika Brückner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(41):13705-13713
A detailed mechanism of hydrogen production by reduction of water with decamethyltitanocene triflate [Cp*2TiIII(OTf)] has been derived for the first time, based on a comprehensive in situ spectroscopic study including EPR and ATR‐FTIR spectroscopy supported by DFT calculations. It is demonstrated that two H2O molecules coordinate to [Cp*2TiIII(OTf)] subsequently forming [Cp2*TiIII(H2O)(OTf)] and [Cp*TiIII(H2O)2(OTf)]. Triflate stabilizes the water ligands by hydrogen bonding. Liberation of hydrogen proceeds only from the diaqua complex [Cp*TiIII(H2O)2(OTf)] and involves, most probably, abstraction and recombination of two H atoms from two molecules of [Cp*TiIII(H2O)2(OTf)] in close vicinity, which is driven by the formation of a strong covalent Ti? OH bond in the resulting final product [Cp*2TiIV(OTf)(OH)]. 相似文献
8.
Prof. Dr. Holger Braunschweig Marco Fuß Dr. Swagat K. Mohapatra Katharina Kraft Dr. Thomas Kupfer Melanie Lang Dr. Krzysztof Radacki Dr. Constantin G. Daniliuc Prof. Dr. Peter G. Jones Prof. Dr. Matthias Tamm 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(38):11732-11743
A novel one‐pot method was developed for the preparation of [Ti(η5‐C5H5)(η7‐C7H7)] (troticene, 1 ) by reaction of sodium cyclopentadienide (NaCp) with [TiCl4(thf)2], followed by reduction of the intermediate [(η5‐C5H5)2TiCl2] with magnesium in the presence of cycloheptatriene (C7H8). The [n]troticenophanes 3 (n=1), 4 , 8 , 10 (n=2), and 11 (n=3) were synthesized by salt elimination reactions between dilithiated troticene, [Ti(η5‐C5H4Li)(η7‐C7H6Li)] ? pmdta ( 2 ) (pmdta=N,N′,N′,N′′,N′′‐pentamethyldiethylenetriamine), and the appropriate organoelement dichlorides Cl2Sn(Mes)2 (Mes=2,4,6‐trimethylphenyl), Cl2Sn2(tBu)4, Cl2B2(NMe2)2, Cl2Si2Me4, and (ClSiMe2)2CH2, respectively. Their structural characterization was carried out by single‐crystal X‐ray diffraction and multinuclear NMR spectroscopy. The stanna[1]‐ and stanna[2]troticenophanes 3 and 4 represent the first heteroleptic sandwich complexes bearing Sn atoms in the ansa bridge. The reaction of 3 with [Pt(PEt3)3] resulted in regioselective insertion of the [Pt(PEt3)2] fragment into the Sn? Cipso bond between the tin atom and the seven‐membered ring, which afforded the platinastanna[2]troticenophane 5 . Oxidative addition was also observed upon treatment of 4 with elemental sulfur or selenium, to produce the [3]troticenophanes [Ti(η5‐C5H4SntBu2)(η7‐C7H6SntBu2)E] ( 6 : E=S; 7 : E=Se). The B? B bond of the bora[2]troticenophane 8 was readily cleaved by reaction with [Pt(PEt3)3] to form the corresponding oxidative addition product [Ti(η5‐C5H4BNMe2)(η7‐C7H6BNMe2)Pt(PEt3)2] ( 9 ). The solid‐state structures of compounds 5 , 6 , and 9 were also determined by single‐crystal X‐ray diffraction. 相似文献
9.
Shubhankar Kumar Bose K. Geetharani V. Ramkumar Shaikh M. Mobin Sundargopal Ghosh Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(48):13483-13490
Reaction of [CpnMCl4?x] (M=V: n=x=2; M=Nb: n=1, x=0) or [Cp*TaCl4] (Cp=η5‐C5H5, Cp*=η5‐C5Me5), with [LiBH4?thf] at ?70 °C followed by thermolysis at 85 °C in the presence of [BH3?thf] yielded the hydrogen‐rich metallaboranes [(CpM)2(B2H6)2] ( 1 : M=V; 2 : M = Nb) and [(Cp*Ta)2(B2H6)2] ( 3 ) in modest to high yields. Complexes 1 and 3 are the first structurally characterized compounds with a metal–metal bond bridged by two hexahydroborate (B2H6) groups forming a symmetrical complex. Addition of [BH3?thf] to 3 results in formation of a metallaborane [(Cp*Ta)2B4H8(μ‐BH4)] ( 4 ) containing a tetrahydroborate ligand, [BH4]?, bound exo to the bicapped tetrahedral cage [(Cp*Ta)2B4H8] by two Ta‐H‐B bridge bonds. The interesting structural feature of 4 is the coordination of the bridging tetrahydroborate group, which has two B? H bonds coordinated to the tantalum atoms. All these new metallaboranes have been characterized by mass, 1H, 11B, and 13C NMR spectroscopy and elemental analysis and the structural types were established unequivocally by crystallographic analysis of 1 – 4 . 相似文献
10.
Reactions of 2‐Substituted Pyridines with Titanocenes and Zirconocenes: Coupling versus Dearomatisation
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Dr. Fabian Reiß Dr. Kai Altenburger Dr. Lisanne Becker Kathleen Schubert Dr. Haijun Jiao Dr. Anke Spannenberg Dr. Dirk Hollmann Dr. Perdita Arndt Prof. Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(10):3361-3369
Reactions of group 4 metallocene sources with 2‐substituted pyridines were investigated to evaluate their coordination type between innocent and reductive dearomatisation as well as to probe the possibility for couplings. A dependence on the cyclopentadienyl ligands (Cp, Cp*), the metals (Ti, Zr), and the substrates (2‐phenyl‐, 2‐acetyl‐, and 2‐iminopyridine) was observed. While 2‐phenylpyridine is barely reactive, 2‐acetylpyridine reacts vigorously with the Cp‐substituted complexes and selectively with their Cp* analogues. With 2‐iminopyridine, in all cases selective reactions were observed. In the isolated [Cp2Ti], [Cp2Zr], and [Cp*2Zr] compounds the substrate coordinates by its pyridyl ring and the unsaturated side‐chain. Subsequently, the pyridine was dearomatised, which is most pronounced in the [Cp*2Zr] compounds. Using [Cp*2Ti] leads to the unexpected paramagnetic complexes [Cp*2TiIII(N,O‐acpy)] and [Cp*2TiIII(N,N′‐impy)]. This highlights the non‐innocent character of the pyridyl substrates. 相似文献
11.
Dennis A. Buschmann Dr. H. Martin Dietrich Dr. David Schneider Dr. Verena M. Birkelbach Dr. Christoph Stuhl Prof. Dr. Karl W. Törnroos Dr. Cäcilia Maichle-Mössmer Prof. Dr. Reiner Anwander 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(47):10834-10840
Tetramethylaluminato/halogenido(X) ligand exchange reactions in half-sandwich complexes [CpRLa(AlMe4)2] are feasible in non-coordinating solvents and provide access to large coordination clusters of the type [CpRLaX2]x. Incomplete exchange reactions generate the hexalanthanum clusters [CpR6La6X8(AlMe4)4] (CpR=Cp*=C5Me5, X=I; CpR=Cp′=C5H4SiMe3, X=Br, I). Treatment of [Cp*La(AlMe4)2] with two equivalents Me3SiI gave the nonalanthanum cluster [Cp*LaI2]9, while the exhaustive reaction of [Cp′La(AlMe4)2] with the halogenido transfer reagents Me3GeX and Me3SiX (X=I, Br, Cl) produced a series of monocyclopentadienyl rare-earth-metal clusters with distinct nuclearity. Depending on the halogenido ion size the homometallic clusters [Cp′LaCl2]10 and [Cp′LaX2]12 (X=Br, I) could be isolated, whereas different crystallization techniques led to the aggregation of clusters of distinct structural motifs, including the desilylated cyclopentadienyl-bridged cluster [(μ-Cp)2Cp′8La8I14] and the heteroaluminato derivative [Cp′10La10Br18(AlBr2Me2)2]. The use of the Cp′ ancillary ligand facilitates cluster characterization by means of NMR spectroscopy. 相似文献
12.
Heiko Jacobsen Heinz Berke Thomas Brackemeyer Tanja Eisenbltter Gerhard Erker Roland Frhlich Oliver Meyer Klaus Bergander 《Helvetica chimica acta》1998,81(9):1692-1709
A density functional theory computational chemistry study has revealed a fundamental structural difference between [Ti(Cp)3]+ and its congeners [Zr(Cp)3]+ and [Hf(Cp)3]+/(Cp=cyclopentadienyl). Whereas the latter two are found to contain three uniformely η5-coordinated Cp ligands (3η5-structural type), [Ti(Cp)3]+ is shown to prefer a 2η5η2 structure. [Ti(Cp)3]+[B(C6F5)3(Me)]− ( 10 ⋅[B(C6F5)3(Me)]−) was experimentally generated by treatment of [Ti(Cp)3(Me)] ( 7a ) with B(C6F5)3 (Scheme 3). Low-temperature 1H-NMR spectroscopy in CDFCl2 (143 K, 600 MHz; Fig. 8) showed a splitting of the Cp resonance into five lines in a 2 : 5 : 2 : 5 : 1 ratio which would be in accord with the theoretically predicted 2η5η2-type structure of [Ti(Cp)3]+. The precursor [Ti(Cp)3(Me)] ( 7a ) exhibits two 1H-NMR Cp resonances in a 10 : 5 ratio in CD2Cl2 at 223 K. Treatment of [HfCl(Cp)2(Me)] ( 6c ) with sodium cyclopentadienide gave [Hf(Cp)3(Me)] ( 7c ) (Scheme 1). Its reaction with B(C6F5)3 furnished the salt [Hf(Cp)3]+[B(C6F5)3(Me)]− ( 8 ⋅[B(C6F5)3(Me)]−), which reacted with tert-butyl isocyanide to give the cationic complex [Hf(Cp)3(C=N−CMe3)]+ ( 9a ; with counterion [B(C6F5)3(Me)]− (Scheme 2). Complex cation 9a was characterized by X-ray diffraction (Fig. 7). Its Hf(Cp3) moiety is of the 3η5-type. The structure is distorted trigonal-pyramidal with an average D−Hf−D angle of 118.8° and an average D−Hf−C(1) angle of 96.5° (D denotes the centroids of the Cp rings; Table 6). Cation 9a is a typical d0-isocyanide complex exhibiting structural parameters of the C≡N−CMe3 group (d(C(1)−N(2))=1.146 (5) Å; IR: v˜(C≡N) 2211 cm−1) very similar to free uncomplexed isonitrile. Analogous treatment of 8 with carbon monoxide yielded the carbonyl (d0-group-4-metal) complex [Hf(Cp)3(CO)]+ ( 9b ; with counterion [B(C6F5)3(Me)]−) (Scheme 2) that was also characterized by X-ray crystal-structure analysis (Fig. 6). Complex 9b is also of the 3η5-structural type, similar to the peviously described cationic complex [Zr(Cp)3(CO)]+, and exhibits properties of the CO ligand (d(C−O)=1.11 (2) Å; IR: v˜(C≡O) 2137 cm−1) very similar to the free carbon monoxide molecule. 相似文献
13.
Heterometallic Complexes with E6 Ligands (E = P, As) The reaction of [Cp*Co(μ-CO)]2 1 with the sandwich complexes [Cp*Fe(η5-E5)] 2 a: E = P, 2 b: E = As in decalin at 190°C affords besides [CpCo2E4] 4: E = P, 7: E = As and [CpFe2P4] 5 the trinuclear complexes [(Cp*Fe)2(Cp*Co)(μ-η2-P2)(μ3-η1:2:1-P2)2] 3 as well as [(Cp*Fe)2(Cp*Co)(μ3-η2:2:2-As3)2] 6 . With [Mo(CO)5(thf)] 3 and 6 form in a build-up reaction the tetranuclear clusters [(Cp*Fe)2(Cp*Co)E6{Mo(CO)3}] 10: E = P, 11: E = As. 3, 6 and 11 have been further characterized by an X-ray crystal structure determination. 相似文献
14.
《Journal of organometallic chemistry》1988,350(2):C20-C24
Thermolysis of [Cp′Ni(μ-CO)]2 (1), Cp′ = η5C5H4R, R = CH3 (1a), t-Bu (1b); [Cp*Ni(μ-CO)]2 (1c), Cp* = η5-C5Me5 and [Cp″Ni(μ-CO)]2 (1d), Cp″ = η5-C5H3R2-1,3, R = t-Bu, with white phosphorus (P4) gives the nickelaphosphacubanes [Cp′Ni(μ3-P)]4 (2a,2b), [(Cp*Ni)3P5] (3) and the cyclo-P3 sandwich [(η3-P3)Ni″η5-C5H3(t-Bu)2] (4), the structure of which has been determined by X-ray crystallography. 相似文献
15.
Prof. Robert D. Robinson Jr. Dr. Werner Kaminsky Prof. Jeremiah J. Scepaniak 《欧洲无机化学杂志》2023,26(27):e202300369
The complexes Cp(MeIm)IrI2 and CpMe4(MeIm)IrCl2 have been prepared and subsequently methylated to form Cp(MeIm)IrMe2 and CpMe4(MeIm)IrMe2 (Cp=η5-C5H5, CpMe4=η5-C5HMe4, MeIm=1,3-dimethylimidazol-2-ylidene). We attempted unsuccessfully to use the dimethyl complexes to study C−D bond activation via methyl-group abstraction. Protonation with one equivalent of a weak acid, such as 2,6-dimethylpyridinium chloride, affords methane and IrIII methyl chloride complexes. 1H-NMR experiments show addition of pyridinium [BArF20]− (BArF20=[B(C6F5)4]−) to the dimethyl species forms [Cp(MeIm)IrMe(py)]+[BArF20]− (py=pyridine) or [CpMe4(MeIm)IrMe(py)]+[BArF20]− respectively, alongside methane, while use of the [BArF20]− salts of more bulky 2,6-dimethylpyridinium and 2,6-di-tert-butylpyridinium gave an intractable mixture. Likewise, the generation of 16 e− species [CpMe4(MeIm)IrMe]+[BArF20]− or [Cp(MeIm)IrMe]+[BarF20]− at low temperature using 2,6-dimethylpyridinium or 2,6-di-tert-butylpyridinium in thawing C6D6 or toluene-d8 formed an intractable mixture and did not lead to C−D bond activation. X-ray structures of several IrIII complexes show similar sterics as that found for the previously reported Cp* analogue. 相似文献
16.
The compound [K([2.2.2]crypt)]Cs7[Sn9]2(en)3 ( 1 ) was synthesized from an alloy of formal composition KCs2Sn9 by dissolving in ethylenediamine (en) followed by the addition of [2.2.2]crypt and toluene. 1 crystallizes in the orthorhombic space group Pcca with a = 45.38(2), b = 9.092(4), c = 18.459(8) Å, and Z = 4. The structure consists of Cs7[Sn9]2 layers which contain [Sn9]4– anions and Cs+ cations. The layers are separated by [K([2.2.2]crypt)]+ units. In the intermetallic slab (Cs7[Sn9]2)– compares the arrangement of pairs of symmetry‐related [Sn9]4– anions with the dimer ([Ge9]–[Ge9])6– in [K([2.2.2]crypt)]2Cs4([Ge9]–[Ge9]), in which the clusters are linked by a cluster‐exo bond. The shortest distance between atoms of such two clusters in 1 is 4.762 Å, e. g. there are no exo Sn‐Sn bonds. The [Sn9]4– anion has almost perfect C4v‐symmetry. 相似文献
17.
Reactions of Group 4 Metallocenes with Monosubstituted Acetonitriles: Keteniminate Formation versus CC Coupling
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Lisanne Becker Dr. Martin Haehnel Dr. Anke Spannenberg Dr. Perdita Arndt Dr. Uwe Rosenthal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(8):3242-3248
The reactions of the Group 4 metallocene dichlorides [Cp′2MCl2] ( 1 a : M=Ti, Cp′=Cp*=η5‐pentamethylcyclopentadienyl, 1 b : M=Zr, Cp′=Cp=η5‐cyclopentadienyl) with lithiated MesCH2?C?N gave [Cp*2TiCl(N=C=C(HMes))] ( 3 ; Mes=mesityl) in the case of 1 a . For compound 1 b , a nitrile–nitrile coupling resulted in a five‐membered bridge in 4 . The reaction of the metallocene alkyne complex [Cp*2Zr(η2‐Me3SiC2SiMe3)] ( 2 ) with PhCH2?C?N led in the first step to the unstable product [Cp*2Zr(η2‐Me3SiC2SiMe3)(NC?CH2Ph)] ( 5 ). After the elimination of the alkyne, a mixture of products was formed. By variation of the solvent and the reaction temperature, three compounds were isolated: a diazadiene complex 6 , a bis(keteniminate) complex 7 , and 8 with a keteniminate ligand and a five‐membered metallacycle. Subsequent variation of the Cp ligand and the metal center by using [Cp2Zr] and [Cp*2Ti] with Me3SiC2SiMe3 in the reactions with PhCH2?C?N gave complex mixtures. 相似文献
18.
Wei‐Cheng Xiong Guang‐Ao Yu Quan Gan Jun Yin Xiang‐Gao Meng Sheng Hua Liu 《应用有机金属化学》2007,21(9):794-797
Formal [2 + 2 + 2] addition reactions of [Cp*Ru(H2O)(NBD)]BF4 (NBD = norbornadiene) with PhC?CR (R = H, COOEt) give [Cp*Ru(η6‐C6H5? C9H8R)] BF4 (1a, R = H; 2a, R = COOEt). Treatment of [Cp*Ru(H2O)(NBD)]BF4 with PhC?C? C?CPh does not give [2 + 2 + 2] addition product, but [Cp*Ru(η6‐C6H5? C?C? C?CPh)] BF4(3a). Treatment of 1a, 2a, 3a with NaBPh4 affords [Cp*Ru(η6‐C6H5? C9H8R)] BPh4 (1b, R = H; 2b, R = COOEt) and [Cp*Ru(η6‐C6H5? C?C? C?CPh)] BPh4(3b). The structures of 1b, 2b and 3b were determined by X‐ray crystallography. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
19.
Dr. Florian Kraus Dipl.‐Chem. Sebastian A. Baer Dr. Magnus R. Buchner Dr. Antti J. Karttunen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(7):2131-2142
The first structural characterization of the text‐book tetraammineberyllium(II) cation [Be(NH3)4]2+, obtained in the compounds [Be(NH3)4]2Cl4 ? 17NH3 and [Be(NH3)4]Cl2, is reported. Through NMR spectroscopic and quantum chemical studies, its hydrolysis products in liquid ammonia were identified. These are the dinuclear [Be2(μ‐OH)(NH3)6]3+ and the cyclic [Be2(μ‐OH)2(NH3)4]2+ and [Be3(μ‐OH)3(NH3)6]3+ cations. The latter species was isolated as the compound [Be3(μ‐OH)3(NH3)6]Cl3 ? 7NH3. NMR analysis of solutions of BeF2 in liquid ammonia showed that the [BeF2(NH3)2] molecule was the only dissolved species. It acts as a strong fluoride‐ion acceptor and forms the [BeF3(NH3)]? anion in the compound [N2H7][BeF3(NH3)]. The compounds presented herein were characterized by single‐crystal X‐ray structure analysis, 9Be, 17O, and 19F NMR, IR, and Raman spectroscopy, deuteration studies, and quantum chemical calculations. The extension of beryllium chemistry to the ammine system shows similarities but also decisive differences to the aquo system. 相似文献
20.
Theocharis C. StamatatosSpyros P. Perlepes Catherine P. RaptopoulouVassilis Psycharis Nikolaos Klouras 《Polyhedron》2011,30(3):451-457
The reactivity pattern of the 16-electron species [M(Cp)2Cl2] (M = Zr, Hf; Cp− = η5-C5H5−) and [Ti(MeCp)2Cl2] (MeCp− = η5-C5H4CH3−) towards the dipicolinate(−2) (dipic2−) ligand under mild (ambient temperature) and convenient (aerobic reactions, aqueous media) conditions have been investigated. The syntheses, molecular structures and spectroscopic (IR, 1H NMR) characterization are reported for the 18-electron products [Zr(Cp)2(dipic)] (1), [Hf(Cp)2(dipic)] (2) and [Ti(MeCp)2(dipic)] (3). The dipic2− ion behaves as N,O,O′-chelating ligand in the three complexes, while the centroids of the Cp− (1, 2) and MeCp− (3) rings formally occupy the fourth and fifth coordination sites about the central metal. The two identical/very similar bite angles of only ∼70° make the dipic2− ligand particularly suited to form stable metallocene derivatives with 5-coordinate geometry. IR and 1H NMR data are discussed in terms of the known structures and the tridentate chelating mode of the dipic2− ligand. 相似文献