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1.
New Trinuclear Complexes of Group 6, 8, and 9 Metals with a Triply Bridging Borylene Ligand 下载免费PDF全文
K. Yuvaraj Moulika Bhattacharyya Rini Prakash V. Ramkumar Prof. Dr. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(26):8889-8896
Trinuclear complexes of group 6, 8, and 9 transition metals with a (μ3‐BH) ligand [(μ3‐BH)(Cp*Rh)2(μ‐CO)M′(CO)5], 3 and 4 ( 3 : M′=Mo; 4 : M′=W) and 5 – 8 , [(Cp*Ru)3(μ3‐CO)2(μ3‐BH)(μ3‐E)(μ‐H){M′(CO)3}] ( 5 : M′=Cr, E=CO; 6 : M′=Mo, E=CO; 7 : M′=Mo, E=BH; 8 : M′=W, E=CO), have been synthesized from the reaction between nido‐[(Cp*M)2B3H7] (nido‐ 1 : M=Rh; nido‐ 2 : M=RuH, Cp*=η5‐C5Me5) and [M′(CO)5 ? thf] (M′=Mo and W). Compounds 3 and 4 are isoelectronic and isostructural with [(μ3‐BH)(Cp*Co)2(μ‐CO)M′(CO)5], (M′=Cr, Mo and W) and [(μ3‐BH)(Cp*Co)2(μ‐CO)(μ‐H)2M′′H(CO)3], (M′′=Mn and Re). All compounds are composed of a bridging borylene ligand (B?H) that is effectively stabilized by a trinuclear framework. In contrast, the reaction of nido‐ 1 with [Cr(CO)5 ? thf] gave [(Cp*Rh)2Cr(CO)3(μ‐CO)(μ3‐BH)(B2H4)] ( 9 ). The geometry of 9 can be viewed as a condensed polyhedron composed of [Rh2Cr(μ3‐BH)] and [Rh2CrB2], a tetrahedral and a square pyramidal geometry, respectively. The bonding of 9 can be considered by using the polyhedral fusion formalism of Mingos. All compounds have been characterized by using different spectroscopic studies and the molecular structures were determined by using single‐crystal X‐ray diffraction analysis. 相似文献
2.
Dudekula Sharmila K. Yuvaraj Subrat Kumar Barik Dipak Kumar Roy Kiran Kumarvarma Chakrahari Rongala Ramalakshmi Bijan Mondal Dr. Babu Varghese Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(45):15219-15225
The synthesis, structural characterization, and reactivity of new bridged borylene complexes are reported. The reaction of [{Cp*CoCl}2] with LiBH4 ? THF at ?70 °C, followed by treatment with [M(CO)3(MeCN)3] (M=W, Mo, and Cr) under mild conditions, yielded heteronuclear triply bridged borylene complexes, [(μ3‐BH)(Cp*Co)2(μ‐CO)M(CO)5] ( 1 – 3 ; 1 : M=W, 2 : M=Mo, 3 : M=Cr). During the syntheses of complexes 1 – 3 , capped‐octahedral cluster [(Cp*Co)2(μ‐H)(BH)4{Co(CO)2}] ( 4 ) was also isolated in good yield. Complexes 1 – 3 are isoelectronic and isostructural to [(μ3‐BH)(Cp*RuCO)2(μ‐CO){Fe(CO)3}] ( 5 ) and [(μ3‐BH)(Cp*RuCO)2(μ‐H)(μ‐CO){Mn(CO)3}] ( 6 ), with a trigonal‐pyramidal geometry in which the μ3‐BH ligand occupies the apical vertex. To test the reactivity of these borylene complexes towards bis‐phosphine ligands, the room‐temperature photolysis of complexes 1 – 3 , 5 , 6 , and [{(μ3‐BH)(Cp*Ru)Fe(CO)3}2(μ‐CO)] ( 7 ) was carried out. Most of these complexes led to decomposition, although photolysis of complex 7 with [Ph2P(CH2)nPPh2] (n=1–3) yielded complexes 9 – 11 , [3,4‐(Ph2P(CH2)nPPh2)‐closo‐1,2,3,4‐Ru2Fe2(BH)2] ( 9 : n=1, 10 : n=2, 11 : n=3). Quantum‐chemical calculations by using DFT methods were carried out on compounds 1 – 3 and 9 – 11 and showed reasonable agreement with the experimentally obtained structural parameters, that is, large HOMO–LUMO gaps, in accordance with the high stabilities of these complexes, and NMR chemical shifts that accurately reflected the experimentally observed resonances. All of the new compounds were characterized in solution by using mass spectrometry, IR spectroscopy, and 1H, 13C, and 11B NMR spectroscopy and their structural types were unequivocally established by crystallographic analysis of complexes 1 , 2 , 4 , 9 , and 10 . 相似文献
3.
Dudekula Sharmila Bijan Mondal Rongala Ramalakshmi Sangita Kundu Dr. Babu Varghese Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):5074-5083
A combined experimental and quantum chemical study of Group 7 borane, trimetallic triply bridged borylene and boride complexes has been undertaken. Treatment of [{Cp*CoCl}2] (Cp*=1,2,3,4,5‐pentamethylcyclopentadienyl) with LiBH4 ? thf at ?78 °C, followed by room‐temperature reaction with three equivalents of [Mn2(CO)10] yielded a manganese hexahydridodiborate compound [{(OC)4Mn}(η6‐B2H6){Mn(CO)3}2(μ‐H)] ( 1 ) and a triply bridged borylene complex [(μ3‐BH)(Cp*Co)2(μ‐CO)(μ‐H)2MnH(CO)3] ( 2 ). In a similar fashion, [Re2(CO)10] generated [(μ3‐BH)(Cp*Co)2(μ‐CO)(μ‐H)2ReH(CO)3] ( 3 ) and [(μ3‐BH)(Cp*Co)2(μ‐CO)2(μ‐H)Co(CO)3] ( 4 ) in modest yields. In contrast, [Ru3(CO)12] under similar reaction conditions yielded a heterometallic semi‐interstitial boride cluster [(Cp*Co)(μ‐H)3Ru3(CO)9B] ( 5 ). The solid‐state X‐ray structure of compound 1 shows a significantly shorter boron–boron bond length. The detailed spectroscopic data of 1 and the unusual structural and bonding features have been described. All the complexes have been characterized by using 1H, 11B, 13C NMR spectroscopy, mass spectrometry, and X‐ray diffraction analysis. The DFT computations were used to shed light on the bonding and electronic structures of these new compounds. The study reveals a dominant B?H?Mn, a weak B?B?Mn interaction, and an enhanced B?B bonding in 1 . 相似文献
4.
Ranjit Bag Sourav Kar Suvam Saha Suman Gomosta Beesam Raghavendra Thierry Roisnel Sundargopal Ghosh 《化学:亚洲杂志》2020,15(6):780-786
Triply‐bridging bis‐{hydrido(borylene)} and bis‐borylene species of groups 6, 8 and 9 transition metals are reported. Mild thermolysis of [Fe2(CO)9] with an in situ produced intermediate, generated from the low‐temperature reaction of [Cp*WCl4] (Cp*=η5‐C5Me5) and [LiBH4?THF] afforded triply‐bridging bis‐{hydrido(borylene)}, [(μ3‐BH)2H2{Cp*W(CO)2}2{Fe(CO)2}] ( 1 ) and bis‐borylene, [(μ3‐BH)2{Cp*W(CO)2}2{Fe(CO)3}] ( 2 ). The chemical bonding analyses of 1 show that the B?H interactions in bis‐{hydrido (borylene)} species is stronger as compared to the M?H ones. Frontier molecular orbital analysis shows a significantly larger energy gap between the HOMO‐LUMO for 2 as compared to 1 . In an attempt to synthesize the ruthenium analogue of 1 , a similar reaction has been performed with [Ru3(CO)12]. Although we failed to get the bis‐{hydrido(borylene)} species, the reaction afforded triply‐bridging bis‐borylene species [(μ3‐BH)2{WCp*(CO)2}2{Ru(CO)3}] ( 2′ ), an analogue of 2 . In search for the isolation of bridging bis‐borylene species of Rh, we have treated [Co2(CO)8] with nido‐[(RhCp*)2(B3H7)], which afforded triply‐bridging bis‐borylene species [(μ3‐BH)2(RhCp*)2Co2(CO)4(μ‐CO)] ( 3 ). All the compounds have been characterized by means of single‐crystal X‐ray diffraction study; 1H, 11B, 13C NMR spectroscopy; IR spectroscopy and mass spectrometry. 相似文献
5.
Dr. Shubhankar Kumar Bose Dipak Kumar Roy Pritam Shankhari K. Yuvaraj Bijan Mondal Amrita Sikder Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(7):2337-2343
Room temperature photolysis of a triply‐bridged borylene complex, [(μ3‐BH)(Cp*RuCO)2(μ‐CO)Fe(CO)3] ( 1 a ; Cp*=C5Me5), in the presence of a series of alkynes, 1,2‐diphenylethyne, 1‐phenyl‐1‐propyne, and 2‐butyne led to the isolation of unprecedented vinyl‐borylene complexes (Z)‐[(Cp*RuCO)2(μ‐CO)B(CR)(CHR′)] ( 2 : R, R′=Ph; 3 : R=Me, R′=Ph; 4 : R, R′=Me). This reaction permits a hydroboration of alkyne through an anti ‐ Markovnikov addition. In stark contrast, in the presence of phenylacetylene, a metallacarborane, closo‐[1,2‐(Cp*Ru)2(μ‐CO)2{Fe2(CO)5}‐4‐Ph‐4,5‐C2BH2] ( 5 a) , is formed. A plausible mechanism has been proposed for the formation of vinyl‐borylene complexes, which is supported by density functional theory (DFT) methods. Furthermore, the calculated 11B NMR chemical shifts accurately reflect the experimentally measured shifts. All the new compounds have been characterized in solution by mass spectrometry and IR, 1H, 11B, and 13C NMR spectroscopies and the structural types were unequivocally established by crystallographic analysis of 2 , 5 a , and 5 b . 相似文献
6.
Investigations of Sb–Sb Bond Formation Reactions in the Coordination Sphere of Transition Metals The reaction of SbCl3 with various transition metal metalates of the type K[MLn] [MLn = Ni(CO)Cp*, Fe(CO)Cp′, Co(CO)4; Cp* = η5‐C5Me5, Cp′ = η5‐C5H4Me] in the presence of [Cr(CO)5thf] have been studied. With K[Ni(CO)Cp*] and K[Fe(CO)2Cp′] the trigonal‐pyramidal complexes [(μ3‐Sb){Ni(CO)Cp*}3] ( 1 ) and [(μ3‐Sb){Fe · (CO)2Cp′}3] ( 2 ), respectively, are obtained. The reaction with K[Co(CO)4] leads to the tetrahedral cluster [Co3(CO)9(μ3‐Sb{Cr(CO)5})] ( 3 ) and the butterfly cluster [Co2(CO)6(μ‐SbCl)(μ‐SbCl{Cr(CO)5})] ( 4 ). All products are characterised by X‐ray crystal structure determination. In contrast to the corresponding [(CO)5CrPCl3] system forming P–P bonds, starting from SbCl3/[Cr(CO)5thf] does not cause a Sb–Sb bond formation. 相似文献
7.
Koushik Saha Sagar Ghorai Sourav Kar Suvam Saha Rajarshi Halder Beesam Raghavendra Eluvathingal D. Jemmis Sundargopal Ghosh 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(49):17848-17853
The room‐temperature reaction of [Cp*TaCl4] with LiBH4?THF followed by addition of S2CPPh3 results in pentahydridodiborate species [(Cp*Ta)2(μ,η2:η2‐B2H5)(μ‐H)(κ2,μ‐S2CH2)2] ( 1 ), a classical [B2H5]? ion stabilized by the binuclear tantalum template. Theoretical studies and bonding analysis established that the unusual stability of [B2H5]? in 1 is mainly due to the stabilization of sp2‐B center by electron donation from tantalum. Reactions to replace the hydrogens attached to the diborane moiety in 1 with a 2 e {M(CO)4} fragment (M=Mo or W) resulted in simple adducts, [{(Cp*Ta)(CH2S2)}2(B2H5)(H){M(CO)3}] ( 6 : M=Mo and 7 : M=W), that retained the diborane(5) unit. 相似文献
8.
Holger Braunschweig Michael Burzler Rian D. Dewhurst Krzysztof Radacki Fabian Seeler 《无机化学与普通化学杂志》2008,634(11):1875-1879
The dimanganese bridging borylene complex [μ‐BMes {(η5‐C5H4Me)Mn(CO)2}2] was synthesized from Mes(Cl)BB(Cl)Mes and K[(η5‐C5H4Me)Mn(CO)2H] at low temperature, providing a small sample after manual separation of crystals, allowing a perfunctory spectroscopic analysis, but affording conclusive X‐ray crystallographic structural data. The trimetallic bridging borylene complex [(μ3‐BCl){{(η5‐C5H4Me)Mn(CO)2} {Pd(PCy3)}2}] was prepared by the addition of [Pd(PCy3)2] to a solution of [μ‐BCl{(η5‐C5H4Me)Mn(CO)2}2], affording pure crystals that were fully characterised including X‐ray crystallographic analysis. The structure is reconciled with detailed theoretical analysis for related model complexes, [(μ3‐BX){{(η5‐C5H5)Mn(CO)2}{Pd(PMe3)}2}] (X = Me, Cl). 相似文献
9.
A. Abel Lozano M. Dolores Santana Gabriel García J. Elaine Barclay Sin C. Davies David J. Evans 《无机化学与普通化学杂志》2005,631(11):2062-2066
A series of heteronuclear nickel‐iron complexes [Fe2(CO)6(μ‐SH)(μ3‐S){NiCl(PPh3)2}] ( 1 ), [Fe2(CO)6(μ‐SH)(μ3‐S){NiCl(dppe)}] ( 2 ), [Fe2(CO)6(μ3‐S)2{Ni(PPh3)2}] ( 3 ), [Fe2(CO)6(μ3‐S)2{Ni(dppe)}] ( 4 ) and [Fe2(CO)6(μ‐SPh)(μ3‐S){NiCl(dppe)}] ( 5 ) have been prepared. The structure of 4 has been determined by X‐ray crystallography. The central metal‐sulfur core of 4 has a trigonal bipyramidal shape with a NiFe2 base plane with two axial sulfur atoms. Each iron atom is 5‐coordinate forming a distorted square pyramid; the nickel is square planar coordinated by two sulfur atoms and two phosphorus atoms. 相似文献
10.
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
11.
Reaction of a labile tungsten nitrile complex, [(Cp*)W(CO)2(NCMe)Me] (Cp*=η5‐C5Me5), with H3SiC(SiMe3)3 gave the hydrido(hydrosilylene) complex [(Cp*)(CO)2(H)W?Si(H){C(SiMe3)3}] ( 1a ). The hydrido(silylene) complex [(η5‐C5Me4Et)(CO)2(H)W?SiMes2] ( 2 ) (Mes=2,4,6‐Me‐C6H2) was synthesized by a similar reaction with H2SiMes2. There is a strong interligand interaction between the hydrido and silylene ligands of these complexes; this was confirmed by a neutron diffraction study of [D2] 1b , that is, the deuterido and η5‐C5Me4Et derivative of 1a . The exchange between the W? H and the Si? D groups was observed in the deuterido complex [D] 1a . This H/D exchange proceeded slowly at room temperature, but very rapidly under UV irradiation. Variable‐temperature NMR spectroscopy measurements show the dynamic behavior of carbonyl ligands in 1a . Complex 1a reacted with acetone at room temperature to give mainly a hydrosilylation product, [(Cp*)(CO)2(H)W?Si(OiPr){C(SiMe3)3}] ( 3a ), along with a siloxy complex, [(Cp*)(CO)2WO(Si(H)iPr{C(SiMe3)3})] ( 4a ). At low temperature, a different reaction, namely, α‐H abstraction, proceeded to give an equilibrium mixture of 1a and a dihydrido(silyl) complex, [(Cp*)(CO)2(H)2W(Si(H){OC(?CH2)Me}{C(SiMe3)3})] ( 5 ). 相似文献
12.
Building upon our earlier results on the chemistry of nido-1,2-[(Cp*RuH)2B3H7] (Cp*=ɳ5-C5Me5) (nido- 1 ) with different transition metal carbonyls, we continued to investigate the reactivity with group 7 metal carbonyls under photolytic condition. Photolysis of nido- 1 with [Mn2(CO)10] led to the isolation of a trimetallic [(Cp*Ru)2{Mn(CO)3}(μ-H)(μ-CO)3(μ3-BH)] ( 2 ) cluster with a triply bridging borylene moiety. Cluster 2 is a rare example of a tetrahedral cluster having hydrido(hydroborylene) moiety. In an attempt to synthesize the Re analogue of 2 , a similar reaction was carried out with [Re2(CO)10] that yielded the trimetallic [(Cp*Ru)2{Re(CO)3}(μ-H)(μ-CO)3(μ3-BH)] ( 3 ) cluster having a triply bridging borylene unit. Along with 3 , a trimetallic square pyramid cluster [(Cp*Ru)2{Re(CO)3}(μ-H)2(μ-CO)(μ3,ɳ2-B2H5)] ( 4 ), and heterotrimetallic hydride clusters [{Cp*Ru(CO)2}-{Re(CO)4}2(μ-H)] ( 5 ) and [{Cp*Ru(CO)}{Re(CO)4}2(μ-H)3] ( 6 ) were isolated. Cluster 4 is a unique example of a M2M′B2 cluster having diboron capped Ru2Re-triangle. The hydride clusters 5 and 6 have triangular RuRe2 frameworks with one and three μ-Hs respectively. All the clusters have been characterized by using mass spectrometry, 1H, 11B{1H}, 13C{1H} NMR and IR spectroscopies analyses and the structures of clusters 2 – 6 have been unambiguously established by XRD analyses. Furthermore, to understand the electronic, structural, and bonding features of the synthesized metal-rich clusters, DFT calculations have been performed. 相似文献
13.
The reinvestigation of an early synthesis of heterometallic cubane-type clusters has led to the isolation of a number of new clusters which have been characterized by spectroscopic and crystallographic techniques. The thermolysis of [(Cp*Mo)(2)B(4)H(4)E(2)] (1: E = S; 2: E = Se; Cp* = η(5)-C(5)Me(5)) in presence of [Fe(2)(CO)(9)] yielded cubane-type clusters [(Cp*Mo)(2)(μ(3)-E)(2)B(2)H(μ-H){Fe(CO)(2)}(2)Fe(CO)(3)], 4 and 5 (4: E = S; 5: E = Se) together with fused clusters [(Cp*Mo)(2)B(4)H(4)E(2)Fe(CO)(2)Fe(CO)(3)] (8: E = S; 9: E = Se). In a similar fashion, reaction of [(Cp*RuCO)(2)B(2)H(6)], 3, with [Fe(2)(CO)(9)] yielded [(Cp*Ru)(2)(μ(3)-CO)(2)B(2)H(μ-H){Fe(CO)(2)}(2)Fe(CO)(3)], 6, and an incomplete cubane cluster [(μ(3)-BH)(3)(Cp*Ru)(2){Fe(CO)(3)}(2)], 7. Clusters 4-6 can be described as heterometallic cubane clusters containing a Fe(CO)(3) moiety exo-bonded to the cubane, while 7 has an incomplete cubane [Ru(2)Fe(2)B(3)] core. The geometry of both compounds 8 and 9 consist of a bicapped octahedron [Mo(2)Fe(2)B(3)E] and a trigonal bipyramidal [Mo(2)B(2)E] core, fused through a common three vertex [Mo(2)B] triangular face. In addition, thermolysis of 3 with [Mn(2)(CO)(10)] permits the isolation of arachno-[(Cp*RuCO)(2)B(3)H(7)], 10. Cluster 10 constitutes a diruthenaborane analogue of 8-sep pentaborane(11) and has a structural isomeric relationship to 1,2-[{Cp*Ru}(2)(CO)(2)B(3)H(7)]. 相似文献
14.
Rongala Ramalakshmi Koushik Saha Dipak Kumar Roy Dr. Babu Varghese Prof. Ashwini K. Phukan Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(48):17191-17195
A series of agostic σ‐borane/borate complexes have been synthesized and structurally characterized from simple borane adducts. A room‐temperature reaction of [Cp*Mo(CO)3Me], 1 with Li[BH3(EPh)] (Cp*=pentamethylcyclopentadienyl, E=S, Se, Te) yielded hydroborate complexes [Cp*Mo(CO)2(μ‐H)BH2EPh] in good yields. With 2‐mercapto‐benzothiazole, an N,S‐carbene‐anchored σ‐borate complex [Cp*Mo(CO)2BH3(1‐benzothiazol‐2‐ylidene)] ( 5 ) was isolated. Further, a transmetalation of the B‐agostic ruthenium complex [Cp*Ru(μ‐H)BHL2] ( 6 , L=C7H4NS2) with [Mn2(CO)10] affords a new B‐agostic complex, [Mn(CO)3(μ‐H)BHL2] ( 7 ) with the same structural motif in which the central metal is replaced by an isolobal and isoelectronic [Mn(CO)3] unit. Natural‐bond‐orbital analyses of 5–7 indicate significant delocalization of the electron density from the filled σB?H orbital to the vacant metal orbital. 相似文献
15.
Dr. Xian‐Kuan Huo Ge Su Prof. Dr. Guo‐Xin Jin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(39):12017-12027
Monophosphine‐o‐carborane has four competitive coordination modes when it coordinates to metal centers. To explore the structural transitions driven by these competitive coordination modes, a series of monophosphine‐o‐carborane Ir,Rh complexes were synthesized and characterized. [Cp*M(Cl)2{1‐(PPh2)‐1,2‐C2B10H11}] (M=Ir ( 1 a ), Rh ( 1 b ); Cp*=η5‐C5Me5), [Cp*Ir(H){7‐(PPh2)‐7,8‐C2B9H11}] ( 2 a ), and [1‐(PPh2)‐3‐(η5‐Cp*)‐3,1,2‐MC2B9H10] (M=Ir ( 3 a ), Rh ( 3 b )) can be all prepared directly by the reaction of 1‐(PPh2)‐1,2‐C2B10H11 with dimeric complexes [(Cp*MCl2)2] (M=Ir, Rh) under different conditions. Compound 3 b was treated with AgOTf (OTf=CF3SO3?) to afford the tetranuclear metallacarborane [Ag2(thf)2(OTf)2{1‐(PPh2)‐3‐(η5‐Cp*)‐3,1,2‐RhC2B9H10}2] ( 4 b ). The arylphosphine group in 3 a and 3 b was functionalized by elemental sulfur (1 equiv) in the presence of Et3N to afford [1‐{(S)PPh2}‐3‐(η5‐Cp*)‐3,1,2‐MC2B9H10] (M=Ir ( 5 a ), Rh ( 5 b )). Additionally, the 1‐(PPh2)‐1,2‐C2B10H11 ligand was functionalized by elemental sulfur (2 equiv) and then treated with [(Cp*IrCl2)2], thus resulting in two 16‐electron complexes [Cp*Ir(7‐{(S)PPh2}‐8‐S‐7,8‐C2B9H9)] ( 6 a ) and [Cp*Ir(7‐{(S)PPh2}‐8‐S‐9‐OCH3‐7,8‐C2B9H9)] ( 7 a ). Compound 6 a further reacted with nBuPPh2, thereby leading to 18‐electron complex [Cp*Ir(nBuPPh2)(7‐{(S)PPh2}‐8‐S‐7,8‐C2B9H10)] ( 8 a ). The influences of other factors on structural transitions or the formation of targeted compounds, including reaction temperature and solvent, were also explored. 相似文献
16.
Chemistry of Diruthenium and Dirhodium Analogues of Pentaborane(9): Synthesis and Characterization of Metal N,S‐Heterocyclic Carbene and B‐Agostic Complexes 下载免费PDF全文
M. Sc. Dipak Kumar Roy M. Sc. Bijan Mondal M. Sc. R. S. Anju Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(9):3640-3648
Building upon our earlier results on the synthesis of electron‐precise transition‐metal–boron complexes, we continue to investigate the reactivity of pentaborane(9) and tetraborane(10) analogues of ruthenium and rhodium towards thiazolyl and oxazolyl ligands. Thus, mild thermolysis of nido‐[(Cp*RuH)2B3H7] ( 1 ) with 2‐mercaptobenzothiazole (2‐mbtz) and 2‐mercaptobenzoxazole (2‐mboz) led to the isolation of Cp*‐based (Cp*=η5‐C5Me5) borate complexes 5 a , b [Cp*RuBH3L] ( 5 a : L=C7H4NS2; 5 b : L=C7H4NOS)) and agostic complexes 7 a , b [Cp*RuBH2(L)2], ( 7 a : L=C7H4NS2; 7 b : L=C7H4NOS). In a similar fashion, a rhodium analogue of pentaborane(9), nido‐[(Cp*Rh)2B3H7] ( 2 ) yielded rhodaboratrane [Cp*RhBH(L)2], 10 (L=C7H4NS2). Interestingly, when the reaction was performed with an excess of 2‐mbtz, it led to the formation of the first structurally characterized N,S‐heterocyclic rhodium‐carbene complex [(Cp*Rh)(L2)(1‐benzothiazol‐2‐ylidene)] ( 11 ) (L=C7H4NS2). Furthermore, to evaluate the scope of this new route, we extended this chemistry towards the diruthenium analogue of tetraborane(10), arachno‐[(Cp*RuCO)2B2H6] ( 3 ), in which the metal center possesses different ancillary ligands. 相似文献
17.
Masahiro Nagaoka Hiroyuki Tsuruda Dr. Masa‐aki Amako Prof. Dr. Hiroharu Suzuki Prof. Dr. Toshiro Takao 《Angewandte Chemie (International ed. in English)》2015,54(49):14871-14874
A μ3‐η2:η2:η2‐silane complex, [(Cp*Ru)3(μ3‐η2:η2:η2‐H3SitBu)(μ‐H)3] ( 2 a ; Cp*=η5‐C5Me5), was synthesized from the reaction of [{Cp*Ru(μ‐H)}3(μ3‐H)2] ( 1 ) with tBuSiH3. Complex 2 a is the first example of a silane ligand adopting a μ3‐η2:η2:η2 coordination mode. This unprecedented coordination mode was established by NMR and IR spectroscopy as well as X‐ray diffraction analysis and supported by a density functional study. Variable‐temperature NMR analysis implied that 2 a equilibrates with a tautomeric μ3‐silyl complex ( 3 a ). Although 3 a was not isolated, the corresponding μ3‐silyl complex, [(Cp*Ru)3(μ3‐η2:η2‐H2SiPh)(H)(μ‐H)3] ( 3 b ), was obtained from the reaction of 1 with PhSiH3. Treatment of 2 a with PhSiH3 resulted in a silane exchange reaction, leading to the formation of 3 b accompanied by the elimination of tBuSiH3. This result indicates that the μ3‐silane complex can be regarded as an “arrested” intermediate for the oxidative addition/reductive elimination of a primary silane to a trinuclear site. 相似文献
18.
Treatment of Co4(CO)12 with an excess of trimethylsilylacetylene (TMSA) in the presence of tri(2‐thienyl)phosphine in THF at 25 °C for 2 hours yielded six compounds. Two pseudo‐octahedral, alkyne‐bridged tetracobalt clusters, [Co4(μ4‐η2‐HC≡CSiMe3)(CO)10(μ‐CO)2] ( 4 ) and [Co4(μ4‐η2‐HC≡CSiMe3)‐(CO)9(μ‐CO)2{P(C4H4S)3}] ( 6 ), along with an alkyne‐bridged dicobalt complex, [Co2(CO)5(μ‐HC≡CSiMe3)‐{P(C4H4S)3}] ( 5 ), were obtained as new compounds. The addition of the thienylphosphine ligand, in fact, facilitates the reaction rate. Reaction of an alkyne‐bridged dicobalt complex, [(η2‐H‐C≡C‐SiMe3)Co2(CO)6] ( 3 ), with a bi‐functional ligand, PPh(‐C≡C‐SiMe3)2, yielded an unexpected six‐membered, cyclic compound, {(Ph)(Me3Si‐C≡C)P‐[(η2‐C≡C‐SiMe3)Co2(CO)5]}2 ( 7 ). All of these new compounds were characterized by spectroscopic means; the solid‐state structures of ( 5 ), ( 6 ) and ( 7 ) have been established by X‐ray crystallography. 相似文献
19.
Prof. Richard D. Adams Joseph Kiprotich Prof. Dmitry V. Peryshkov Dr. Yuen Onn Wong 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6501-6504
The reaction of Os3(CO)10(NCMe)2 with closo‐o‐C2B10H10 has yielded two interconvertible isomers Os3(CO)9(μ3‐4,5,9‐C2B10H8)(μ‐H)2 ( 1 a ) and Os3(CO)9(μ3‐3,4,8‐C2B10H8)(μ‐H)2 ( 1 b ) formed by the loss of the two NCMe ligands and one CO ligand from the Os3 cluster. Two BH bonds of the o‐C2B10H10 were activated in its addition to the osmium cluster. A second triosmium cluster was added to the 1 a / 1 b mixture to yield the complex Os3(CO)9(μ‐H)2(μ3‐4,5,9‐μ3‐7,11,12‐C2B10H7)Os3(CO)9(μ‐H)3 ( 2 ) that contains two triosmium triangles attached to the same carborane cage. When heated, 2 was transformed to the complex Os3(CO)9(μ‐H)(μ3‐3,4,8‐μ3‐7,11,12‐C2B10H8)Os3(CO)9(μ‐H) ( 3 ) by a novel opening of the carborane cage with loss of H2. 相似文献
20.
Koushik Saha Benson Joseph Rongala Ramalakshmi Dr. R. S. Anju Dr. Babu Varghese Prof. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(23):7871-7878
Thermolysis of [Cp*Ru(PPh2(CH2)PPh2)BH2(L2)] 1 (Cp*=η5‐C5Me5; L=C7H4NS2), with terminal alkynes led to the formation of η4‐σ,π‐borataallyl complexes [Cp*Ru(μ‐H)B{R‐C=CH2}(L)2] ( 2 a – c ) and η2‐vinylborane complexes [Cp*Ru(R‐C=CH2)BH(L)2] ( 3 a – c ) ( 2 a , 3 a : R=Ph; 2 b , 3 b : R=COOCH3; 2 c , 3 c : R=p‐CH3‐C6H4; L=C7H4NS2) through hydroboration reaction. Ruthenium and the HBCC unit of the vinylborane moiety in 2 a – c are linked by a unique η4‐interaction. Conversions of 1 into 3 a – c proceed through the formation of intermediates 2 a – c . Furthermore, in an attempt to expand the library of these novel complexes, chemistry of σ‐borane complex [Cp*RuCO(μ‐H)BH2L] 4 (L=C7H4NS2) was investigated with both internal and terminal alkynes. Interestingly, under photolytic conditions, 4 reacts with methyl propiolate to generate the η4‐σ,π‐borataallyl complexes [Cp*Ru(μ‐H)BH{R‐C=CH2}(L)] 5 and [Cp*Ru(μ‐H)BH{HC=CH‐R}(L)] 6 (R=COOCH3; L=C7H4NS2) by Markovnikov and anti‐Markovnikov hydroboration. In an extension, photolysis of 4 in the presence of dimethyl acetylenedicarboxylate yielded η4‐σ,π‐borataallyl complex [Cp*Ru(μ‐H)BH{R‐C=CH‐R}(L)] 7 (R=COOCH3; L=C7H4NS2). An agostic interaction was also found to be present in 2 a – c and 5 – 7 , which is rare among the borataallyl complexes. All the new compounds have been characterized in solution by IR, 1H, 11B, 13C NMR spectroscopy, mass spectrometry and the structural types were unequivocally established by crystallographic analysis of 2 b , 3 a – c and 5 – 7 . DFT calculations were performed to evaluate possible bonding and electronic structures of the new compounds. 相似文献