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The first (tricarbollide)rhodium halide complexes
Inorganic Chemistry Communications 14 (2011) 313–315
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Inorganic Chemistry Communications j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / i n o c h e
The first (tricarbollide)rhodium halide complexes Dmitry A. Loginov a, Zoya A. Starikova a, Pavel V. Petrovskii a, Josef Holub b, Alexander R. Kudinov a,⁎ a
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 ul. Vavilova, 119991 Moscow GSP-1, Russian Federation Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic (Research Centre for New Inorganic Compounds and Advanced Materials, University of Pardubice), 250 68, Rež, Czech Republic b
a r t i c l e
i n f o
Article history: Received 1 June 2010 Accepted 17 November 2010 Available online 26 November 2010 Keywords: Boranes Metallacarboranes Rhodium Tricarbollide
a b s t r a c t Reactions of (η-1-tBuNH-1,7,9-C3B8H10)Rh(cod) with Br2 or I2 give complexes [(η-1-tBuNH-1,7,9-C3B8H10) RhX2]2 (X= Br (2a), I (2b)). Reaction of 2b with TlBF4 affords cation [(η-1-tBuNH-1,7,9-C3B8H10)2Rh2(μ-I)3]+ (3). Complex 2a reacts with Tl[Tl(η-7,8-C2B9H11)] giving the bis(carborane) complex (η-1-tBuNH-1,7,9-C3B8H10)Rh (η-7,8-C2B9H11) (4). Structures of 2a,b were determined by X-ray diffraction.] © 2010 Elsevier B.V. All rights reserved.
The cyclopentadienyl rhodium and iridium complexes [Cp ⁎ MX2]2 (X = Cl, Br, I) are widely used in organometallic synthesis and homogeneous catalysis [1]. ‘Charge-compensated’ dicarbollides [LC2B9H10]– (L = SMe2, NMe3) [2] and tricarbollides [C3B8H11]− [3] have a single negative charge making them similar with Cp− in coordinating ability towards transition metals. Earlier we have synthesized halide complexes [(η-9-SMe 2 -7,8-C 2 B 9 H 10 )MX 2 ] 2 (M = Rh, Ir) by reactions of cyclooctadiene derivatives (η-9-SMe27,8-C2B9H10)M(cod) with hydrohalic acids [4]. They were used as synthons of the [(η-9-SMe2-7,8-C2B9H10)M]2+ fragments [4,5]. Herein we report the synthesis of the first (tricarbollide)rhodium halide complexes [(η-1-tBuNH-1,7,9-C3B8H10)RhX2]2 (X = Br, I). Their reactivity and structures are also discussed. Previously we have synthesized (cyclooctadiene)rhodatricarborane (η-1-tBuNH-1,7,9-C3B8H10)Rh(cod) (1) in 96% yield by reaction of Tl[7-tBuNH-7,8,9-C3B8H10] with [(cod)Rh(THF)3]+ in THF (generated in situ by interaction of [(cod)RhCl]2 with Ag+) [6]. In the present work we found that complex 1 can be also prepared in the same yield by direct reaction with [(cod)RhCl]2 in acetone [7]. Noteworthy, the reaction is accompanied by room-temperature polyhedral rearrangement which is typical for the complexation of anion [7-tBuNH-7,8,9C3B8H10]– with transition metals [6,8]. The subsequent reactions of 1 with Br2 or I2 give the halide complexes [(η-1-tBuNH-1,7,9-C3B8H10) RhX2]2 (X = Br (2a), I (2b)) in 93–96% yields (Scheme 1) [9]. Noteworthy, the use of HX instead of X2 (as in the synthesis of [(η9-SMe2-7,8-C2B9H10)RhX2]2 [4]) does not lead to 2a,b owing to the protonation of the amino group.
⁎ Corresponding author. Fax: +7 499 1355085. E-mail address: [email protected] (A.R. Kudinov). 1387-7003/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.inoche.2010.11.024
The reaction of 2b with TlBF4 affords the cationic dinuclear complex [(η-1-tBuNH-1,7,9-C3B8H10)2Rh2(μ-I)3]BF4 ([3]BF4) as a result of abstraction of one iodide anion (Scheme 2) [10]. The reaction of 2a with Tl[Tl(η-7,8-C2B9H11)] leads to the unsymmetrical bis (carborane) complex (η-1-tBuNH-1,7,9-C3B8H10)Rh(η-7,8-C2B9H11) (4) containing both dicarbollide and tricarbollide ligands [11]. This reaction illustrates the utility of complexes 2a,b as synthons of the rhodatricarborane fragment [(η-1-tBuNH-1,7,9-C3B8H10)Rh]2+. Complexes 2a,b are indefinitely stable in air. They are well soluble in CHCl3 and CH2Cl2 (unlike the ‘charge-compensated’ dicarbollide analogues [(η-9-SMe2-7,8-C2B9H10)MX2]2 which are insoluble in all known solvents [4]). It allowed us to obtain single crystals of 2a,b suitable for Xray diffraction study [12]. This study revealed that they have dimeric
Scheme 1. Synthesis of the halide complexes 2a,b.
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D.A. Loginov et al. / Inorganic Chemistry Communications 14 (2011) 313–315
Scheme 2. Reactions of 2a,b with TlBF4 and Tl[Tl(η-7,8-C2B9H11)].
structures (Figs. 1 and 2), similar to the cyclopentadienyl derivatives [Cp⁎RhX2]2 [13]. Only one example of dimeric rhodacarborane with bridging halide ligands, {3-[η1-SC(NHPh)N(Ph)-CH2]-3-Br-3,1,2RhC2B9H10}2, has been previously structurally characterized [14]. Interestingly, the distance from the Rh atom to the C atom located in trans-position to the terminal halogen is longer than the second Rh–C distance. As a matter of fact, the Rh–C9 bond (av. 2.188 Å in 2a, 2.237 Å in 2b) is longer than Rh–C7 (av. 2.163 Å in 2a, 2.198 Å in 2b).
It can be explained by greater loosening trans-effect of the terminal halogen atom compared with the bridging one. The Rh⋯C2B3 distance in 2b (1.596 Å) is longer than that in 2a (av. 1.553 Å), suggesting weaker bonding of the rhodium atom with tricarbollide ligand in the iodide 2b. It is apparently connected with stronger bonding of the I atoms compared with Br. In both compounds the pentagonal C2B3 face is folded along the C7⋯C9 line by ca 10.0° for 2a and 11.5° for 2b so that the Rh–C bonds are longer than the Rh–B
Fig. 1. Structure of 2a. Ellipsoids are shown at the 50% level. All hydrogen atoms except H1 and H1A are omitted for clarity. Selected bond lengths (Å): Rh1–Br1 2.4616(5), Rh1–Br2 2.5964(5), Rh1–Br2A 2.5449(5), Rh1A–Br1A 2.4742(5), Rh1A–Br2 2.5188(5), Rh1A–Br2A 2.6369(5), Rh1–C7 2.163(4), Rh1–B8 2.117(4), Rh1–C9 2.196(4), Rh1–B10 2.132(4), Rh1– B11 2.157(4), Rh1A–C7A 2.164(4), Rh1A–B8A 2.119(4), Rh1A–C9A 2.179(3), Rh1A–B10A 2.133(4), Rh1A–B11A 2.152(5), C1–N1 1.397(4), N1–C2 1.477(5), C1A–N1A 1.407(5), N1A–C2A 1.480(5) (2).
Fig. 2. Structure of 2b. Ellipsoids are shown at the 50% level. All hydrogen atoms except H1 and H1A are omitted for clarity. Selected bond lengths (Å): Rh1–I1 2.6619(8), Rh1–I1A 2.7445(8), Rh1–I2 2.6673(8), Rh1–C7 2.198(8), Rh1–B8 2.155(8), Rh1–C9 2.237(7), Rh1–B10 2.149(9), Rh1–B11 2.160(9), C1–N1 1.403(10), N1–C2 1.485(10).
D.A. Loginov et al. / Inorganic Chemistry Communications 14 (2011) 313–315
bonds. Such folding is typical for complexes with the [1-tBuNH-1,7,9C3B8H10]− ligand [6,8,15]. In conclusion, reactions of the cyclooctadiene derivative 1 with halogens give the (tricarbollide)rhodium halide complexes 2a,b. Xray diffraction study proven their dimeric structure similar to [Cp ⁎ RhX2]2. The utility of 2a,b as synthons of the rhodatricarborane fragment [(η-1-tBuNH-1,7,9-C3B8H10)Rh]2+ was demonstrated.
[6] [7]
Acknowledgement J.H. thanks the Ministry of Education, Youth and Sport of the Czech Republic (Grant No. LC 523).
[8]
Appendix A. Supplementary material CCDC 779008 and 779009 contain the supplementary crystallographic data for 2a,b. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/ data_request/cif.
[9]
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c M. Corsini, S. Losi, E. Grigiotti, F. Rossi, P. Zanello, A.R. Kudinov, D.A. Loginov, M.M. Vinogradov, Z.A. Starikova, J. Solid State Electrochem. 11 (2007) 1643; d D.A. Loginov, D.V. Muratov, A.R. Kudinov, Izv. Akad. Nauk Ser. Khim. (2008) 1; Russ. Chem. Bull. 57 (2008) 18 (Engl. Transl.); e A.R. Kudinov, D.A. Loginov, Izv. Akad. Nauk Ser. Khim. (2009) 586; Russ. Chem. Bull. 58 (2009) 6008 (Engl. Transl.). D.S. Perekalin, K.A. Lyssenko, P.V. Petrovskii, J. Holub, B. Štíbr, A.R. Kudinov, J. Organomet. Chem. 690 (2005) 2775. A mixture of [(cod)RhCl]2 (150 mg, 0.30 mmol) and Tl[7-tBuNH-7,8,9-C3B8H10] (262 mg, 0.64 mmol) in acetone (2 ml) was stirred overnight in inert atmosphere. The solvent was removed in vacuo. The residue was extracted with petroleum ether. After evaporation of the solvent, complex 1 was obtained as a yellow crystalline solid. Yield 243 mg (96%). For spectral data see Ref. 6. a B. Grüner, F. Teixidor, C. Vinas, R. Sillanpää, R. Kivekäs, B. Štíbr, J. Chem. Soc. Dalton Trans. (1999) 3337; b J. Holub, B. Grüner, D.S. Perekalin, D.G. Golovanov, K.A. Lyssenko, P.V. Petrovskii, A.R. Kudinov, B. Štíbr, Inorg. Chem. 44 (2005) 1655; c D.A. Loginov, M.M. Vinogradov, Z.A. Starikova, P.V. Petrovskii, J. Holub, A.R. Kudinov, Izv. Akad. Nauk Ser. Khim. (2008) 2250; Russ. Chem. Bull. 57 (2008) 22948 (Engl. Transl.). A solution of X2 (0.36 mmol) in ether (2 ml) was added to 1 (150 mg, 0.36 mmol) in the same solvent (2 ml) and reaction mixture was stirred for ca. 0.5 h (an inert atmosphere is not necessary). The brown-black precipitate formed was centrifuged off and washed by ether. 2a, X = Br, yield 156 mg (93%). 1H NMR (CDCl3): δ = 4.68 (s, 1H, NH), 3.57 (s, 2H, CH), 1.24 (s, 9H, tBu). 11B{1H} NMR (CDCl3): δ = − 0.6 (3B), − 12.5 (2B), − 15.4 (2B), − 17.1 (1B). Found (%): C, 18.07; H, 4.29; N, 2.91; B, 18.45. Calc. for C7H20B8Br2NRh (%): C, 17.98; H, 4.31; N, 3.00; B, 18.50. 2b, X = I, yield 193 mg (96%). 1H NMR (acetone-d6): δ=4.61 (s, 1H, NH), 3.47 (m, 2H, CH), 1.25 (s, 9H, tBu). 11B{1H} NMR (CDCl3): δ = − 3.4 (3B), − 12.5 (2B), − 15.7 (2B), − 17.5 (1B). Found (%): C, 15.03; H, 3.49; N, 2.49; B, 15.37. Calc. for C7H20B8I2NRh (%): C, 14.97; H, 3.59; N, 2.49; B, 15.40. Dichloromethane (2 ml) was added to a mixture of complex 2b (30 mg, 0.03 mmol) and TlBF4 (15 mg, 0.05 mmol). The reaction mixture was stirred overnight. The precipitate of TlI was filtered off. The solvent was removed in vacuo and the residue repricipitated from CH2Cl2 by petroleum ether. Yield 27 mg (93%) of [3]BF4 as a brown solid. 1H NMR (acetone-d6): δ = 5.11 (s, 1H, NH), 3.69 (s, 2H, CH), 1.32 (s, 9H, tBu). 11B{1H} NMR (acetone-d6): δ=−0.9 (1B, BF4),−2.1 (4B), − 6.9 (2B), − 9.2 (2B), − 15.7 (8B). Found (%): C, 15.39; H, 3.71; N, 2.51; B, 16.38. Calc. for C14H40B17F4I3N2Rh2 (%): C, 15.53; H, 3.72; N, 2.59; B, 16.97. Acetonitrile (2 ml) was added to a mixture of complex 2a (47 mg, 0.05 mmol) and Tl[Tl(η-7,8–C2B9H11)] (64 mg, 0.12 mmol). The reaction mixture was stirred overnight. The solvent was removed in vacuo. The residue was dissolved in CH2Cl2 and eluted through a layer (5 cm) of silica gel by the same solvent. The volume of the filtrate was reduced to ca. 0.5 ml in vacuo. Addition of petroleum ether (10 ml) precipitated 4 as a white solid, which was filtered off and dried in vacuo. Yield 20 mg (45%). 1H NMR (CDCl3): δ = 4.27 (s, 2 H, CH), 2.81 (s, 2 H, CH), 1.31 (s, 9 H, tBu). 11B{1H} NMR (CDCl3): δ = 8.4 (2B),− 3.3 (2B),− 5.0 (4B),− 12.0 (2B), − 14.0 (4B),− 19.0 (2B),− 21.2 (1B). Found (%): C, 24.38; H, 7.14; N, 3.05; B, 41.93. Calc. for C9H31B17NRh (%): C, 24.56; H, 7.10; N, 3.18; B, 41.77. Crystals of 2a,b were grown up by slow diffusion in a two-layer system: a solution of complex in CH2Cl2/petroleum ether. Crystal data for 2a: C14H40B16Br4N2Rh2, monoclinic, space group P21/c, a=13.9730(10) Å, b=12.5361(9) Å, c=17.8337(13) Å, β=94.2340(10)° V=3115.3(4) Å3, Z=4, dcalc =1.993 g cm− 3, μ=6.203 mm− 1, crystal size 0.45×0.35×0.20 mm, F(000)=1792, Tmin/Tmax 0.083/0.285, R1=0.0334 (from 5613 unique reflections with IN 2σ(I)) and wR2=0.0763 (from all 7420 unique reflections). Crystal data for 2b: C14H40B16I4N2Rh2, monoclinic, space group P21/n, a=15.4009(9) Å, b=6.5682(4) Å, c=17.1162(10) Å, β=112.1790(10)° V=1603.30 (16) Å 3 , Z = 2, d c a l c = 2.326 g cm − 3 , μ = 4.894 mm − 1 , crystal size 0.50×0.30×0.05 mm, F(000)=1040, Tmin/Tmax 0.187/0.783, R1=0.0448 (from 2665 unique reflections with IN 2σ(I)) and wR2=0.1045 (from all 3025 unique reflections). Single-crystal X-ray diffraction experiments were carried out with a Bruker SMART 1000 CCD area detector, using graphite monochromated Mo-Kα radiation (λ=0.71073 Å). The structures were solved by direct method and refined by the full-matrix least-squares against F2 in anisotropic approximation (for nonhydrogen atoms). The hydrogen atoms of the BH groups were found in the difference Fourier synthesis, and the positions of other hydrogen atoms were calculated. All hydrogen atoms were refined in isotropic approximation in riding model with the Uiso(H) parameters equal to 1.5 Ueq(Ci) for methyl groups and to 1.2 Ueq (Cii) and 1.2 Ueq(Bi) for other atoms, were Ueq(B) and Ueq(C) are the equivalent thermal parameters of the atoms to which the corresponding H atoms are bound. All calculations were performed using the SHELXTL software: G. M. Sheldrick, SHELXTL, Version 5.10, Bruker AXS Inc., Madison, WI, USA, 1998. a M.R. Churchill, S.A. Julis, F.J. Rotella, Inorg. Chem. 16 (1977) 1137; b M.R. Churchill, S.A. Julis, Inorg. Chem. 17 (1978) 3011; c M.R. Churchill, S.A. Julis, Inorg. Chem. 18 (1979) 2918. G. Ferguson, T.R. Spalding, P.A. McEneaney, Acta Cryst. C51 (1995) 1501. E.V. Mutseneck, D.S. Perekalin, J. Holub, K.A. Lyssenko, P.V. Petrovskii, B. Štíbr, A.R. Kudinov, Eur. J. Inorg. Chem. (2006) 1737.
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Inorganic Chemistry Communications j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / i n o c h e
The first (tricarbollide)rhodium halide complexes Dmitry A. Loginov a, Zoya A. Starikova a, Pavel V. Petrovskii a, Josef Holub b, Alexander R. Kudinov a,⁎ a
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 ul. Vavilova, 119991 Moscow GSP-1, Russian Federation Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic (Research Centre for New Inorganic Compounds and Advanced Materials, University of Pardubice), 250 68, Rež, Czech Republic b
a r t i c l e
i n f o
Article history: Received 1 June 2010 Accepted 17 November 2010 Available online 26 November 2010 Keywords: Boranes Metallacarboranes Rhodium Tricarbollide
a b s t r a c t Reactions of (η-1-tBuNH-1,7,9-C3B8H10)Rh(cod) with Br2 or I2 give complexes [(η-1-tBuNH-1,7,9-C3B8H10) RhX2]2 (X= Br (2a), I (2b)). Reaction of 2b with TlBF4 affords cation [(η-1-tBuNH-1,7,9-C3B8H10)2Rh2(μ-I)3]+ (3). Complex 2a reacts with Tl[Tl(η-7,8-C2B9H11)] giving the bis(carborane) complex (η-1-tBuNH-1,7,9-C3B8H10)Rh (η-7,8-C2B9H11) (4). Structures of 2a,b were determined by X-ray diffraction.] © 2010 Elsevier B.V. All rights reserved.
The cyclopentadienyl rhodium and iridium complexes [Cp ⁎ MX2]2 (X = Cl, Br, I) are widely used in organometallic synthesis and homogeneous catalysis [1]. ‘Charge-compensated’ dicarbollides [LC2B9H10]– (L = SMe2, NMe3) [2] and tricarbollides [C3B8H11]− [3] have a single negative charge making them similar with Cp− in coordinating ability towards transition metals. Earlier we have synthesized halide complexes [(η-9-SMe 2 -7,8-C 2 B 9 H 10 )MX 2 ] 2 (M = Rh, Ir) by reactions of cyclooctadiene derivatives (η-9-SMe27,8-C2B9H10)M(cod) with hydrohalic acids [4]. They were used as synthons of the [(η-9-SMe2-7,8-C2B9H10)M]2+ fragments [4,5]. Herein we report the synthesis of the first (tricarbollide)rhodium halide complexes [(η-1-tBuNH-1,7,9-C3B8H10)RhX2]2 (X = Br, I). Their reactivity and structures are also discussed. Previously we have synthesized (cyclooctadiene)rhodatricarborane (η-1-tBuNH-1,7,9-C3B8H10)Rh(cod) (1) in 96% yield by reaction of Tl[7-tBuNH-7,8,9-C3B8H10] with [(cod)Rh(THF)3]+ in THF (generated in situ by interaction of [(cod)RhCl]2 with Ag+) [6]. In the present work we found that complex 1 can be also prepared in the same yield by direct reaction with [(cod)RhCl]2 in acetone [7]. Noteworthy, the reaction is accompanied by room-temperature polyhedral rearrangement which is typical for the complexation of anion [7-tBuNH-7,8,9C3B8H10]– with transition metals [6,8]. The subsequent reactions of 1 with Br2 or I2 give the halide complexes [(η-1-tBuNH-1,7,9-C3B8H10) RhX2]2 (X = Br (2a), I (2b)) in 93–96% yields (Scheme 1) [9]. Noteworthy, the use of HX instead of X2 (as in the synthesis of [(η9-SMe2-7,8-C2B9H10)RhX2]2 [4]) does not lead to 2a,b owing to the protonation of the amino group.
⁎ Corresponding author. Fax: +7 499 1355085. E-mail address: [email protected] (A.R. Kudinov). 1387-7003/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.inoche.2010.11.024
The reaction of 2b with TlBF4 affords the cationic dinuclear complex [(η-1-tBuNH-1,7,9-C3B8H10)2Rh2(μ-I)3]BF4 ([3]BF4) as a result of abstraction of one iodide anion (Scheme 2) [10]. The reaction of 2a with Tl[Tl(η-7,8-C2B9H11)] leads to the unsymmetrical bis (carborane) complex (η-1-tBuNH-1,7,9-C3B8H10)Rh(η-7,8-C2B9H11) (4) containing both dicarbollide and tricarbollide ligands [11]. This reaction illustrates the utility of complexes 2a,b as synthons of the rhodatricarborane fragment [(η-1-tBuNH-1,7,9-C3B8H10)Rh]2+. Complexes 2a,b are indefinitely stable in air. They are well soluble in CHCl3 and CH2Cl2 (unlike the ‘charge-compensated’ dicarbollide analogues [(η-9-SMe2-7,8-C2B9H10)MX2]2 which are insoluble in all known solvents [4]). It allowed us to obtain single crystals of 2a,b suitable for Xray diffraction study [12]. This study revealed that they have dimeric
Scheme 1. Synthesis of the halide complexes 2a,b.
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D.A. Loginov et al. / Inorganic Chemistry Communications 14 (2011) 313–315
Scheme 2. Reactions of 2a,b with TlBF4 and Tl[Tl(η-7,8-C2B9H11)].
structures (Figs. 1 and 2), similar to the cyclopentadienyl derivatives [Cp⁎RhX2]2 [13]. Only one example of dimeric rhodacarborane with bridging halide ligands, {3-[η1-SC(NHPh)N(Ph)-CH2]-3-Br-3,1,2RhC2B9H10}2, has been previously structurally characterized [14]. Interestingly, the distance from the Rh atom to the C atom located in trans-position to the terminal halogen is longer than the second Rh–C distance. As a matter of fact, the Rh–C9 bond (av. 2.188 Å in 2a, 2.237 Å in 2b) is longer than Rh–C7 (av. 2.163 Å in 2a, 2.198 Å in 2b).
It can be explained by greater loosening trans-effect of the terminal halogen atom compared with the bridging one. The Rh⋯C2B3 distance in 2b (1.596 Å) is longer than that in 2a (av. 1.553 Å), suggesting weaker bonding of the rhodium atom with tricarbollide ligand in the iodide 2b. It is apparently connected with stronger bonding of the I atoms compared with Br. In both compounds the pentagonal C2B3 face is folded along the C7⋯C9 line by ca 10.0° for 2a and 11.5° for 2b so that the Rh–C bonds are longer than the Rh–B
Fig. 1. Structure of 2a. Ellipsoids are shown at the 50% level. All hydrogen atoms except H1 and H1A are omitted for clarity. Selected bond lengths (Å): Rh1–Br1 2.4616(5), Rh1–Br2 2.5964(5), Rh1–Br2A 2.5449(5), Rh1A–Br1A 2.4742(5), Rh1A–Br2 2.5188(5), Rh1A–Br2A 2.6369(5), Rh1–C7 2.163(4), Rh1–B8 2.117(4), Rh1–C9 2.196(4), Rh1–B10 2.132(4), Rh1– B11 2.157(4), Rh1A–C7A 2.164(4), Rh1A–B8A 2.119(4), Rh1A–C9A 2.179(3), Rh1A–B10A 2.133(4), Rh1A–B11A 2.152(5), C1–N1 1.397(4), N1–C2 1.477(5), C1A–N1A 1.407(5), N1A–C2A 1.480(5) (2).
Fig. 2. Structure of 2b. Ellipsoids are shown at the 50% level. All hydrogen atoms except H1 and H1A are omitted for clarity. Selected bond lengths (Å): Rh1–I1 2.6619(8), Rh1–I1A 2.7445(8), Rh1–I2 2.6673(8), Rh1–C7 2.198(8), Rh1–B8 2.155(8), Rh1–C9 2.237(7), Rh1–B10 2.149(9), Rh1–B11 2.160(9), C1–N1 1.403(10), N1–C2 1.485(10).
D.A. Loginov et al. / Inorganic Chemistry Communications 14 (2011) 313–315
bonds. Such folding is typical for complexes with the [1-tBuNH-1,7,9C3B8H10]− ligand [6,8,15]. In conclusion, reactions of the cyclooctadiene derivative 1 with halogens give the (tricarbollide)rhodium halide complexes 2a,b. Xray diffraction study proven their dimeric structure similar to [Cp ⁎ RhX2]2. The utility of 2a,b as synthons of the rhodatricarborane fragment [(η-1-tBuNH-1,7,9-C3B8H10)Rh]2+ was demonstrated.
[6] [7]
Acknowledgement J.H. thanks the Ministry of Education, Youth and Sport of the Czech Republic (Grant No. LC 523).
[8]
Appendix A. Supplementary material CCDC 779008 and 779009 contain the supplementary crystallographic data for 2a,b. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/ data_request/cif.
[9]
References [1] a b c d e [2] a b c d e f g h
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c M. Corsini, S. Losi, E. Grigiotti, F. Rossi, P. Zanello, A.R. Kudinov, D.A. Loginov, M.M. Vinogradov, Z.A. Starikova, J. Solid State Electrochem. 11 (2007) 1643; d D.A. Loginov, D.V. Muratov, A.R. Kudinov, Izv. Akad. Nauk Ser. Khim. (2008) 1; Russ. Chem. Bull. 57 (2008) 18 (Engl. Transl.); e A.R. Kudinov, D.A. Loginov, Izv. Akad. Nauk Ser. Khim. (2009) 586; Russ. Chem. Bull. 58 (2009) 6008 (Engl. Transl.). D.S. Perekalin, K.A. Lyssenko, P.V. Petrovskii, J. Holub, B. Štíbr, A.R. Kudinov, J. Organomet. Chem. 690 (2005) 2775. A mixture of [(cod)RhCl]2 (150 mg, 0.30 mmol) and Tl[7-tBuNH-7,8,9-C3B8H10] (262 mg, 0.64 mmol) in acetone (2 ml) was stirred overnight in inert atmosphere. The solvent was removed in vacuo. The residue was extracted with petroleum ether. After evaporation of the solvent, complex 1 was obtained as a yellow crystalline solid. Yield 243 mg (96%). For spectral data see Ref. 6. a B. Grüner, F. Teixidor, C. Vinas, R. Sillanpää, R. Kivekäs, B. Štíbr, J. Chem. Soc. Dalton Trans. (1999) 3337; b J. Holub, B. Grüner, D.S. Perekalin, D.G. Golovanov, K.A. Lyssenko, P.V. Petrovskii, A.R. Kudinov, B. Štíbr, Inorg. Chem. 44 (2005) 1655; c D.A. Loginov, M.M. Vinogradov, Z.A. Starikova, P.V. Petrovskii, J. Holub, A.R. Kudinov, Izv. Akad. Nauk Ser. Khim. (2008) 2250; Russ. Chem. Bull. 57 (2008) 22948 (Engl. Transl.). A solution of X2 (0.36 mmol) in ether (2 ml) was added to 1 (150 mg, 0.36 mmol) in the same solvent (2 ml) and reaction mixture was stirred for ca. 0.5 h (an inert atmosphere is not necessary). The brown-black precipitate formed was centrifuged off and washed by ether. 2a, X = Br, yield 156 mg (93%). 1H NMR (CDCl3): δ = 4.68 (s, 1H, NH), 3.57 (s, 2H, CH), 1.24 (s, 9H, tBu). 11B{1H} NMR (CDCl3): δ = − 0.6 (3B), − 12.5 (2B), − 15.4 (2B), − 17.1 (1B). Found (%): C, 18.07; H, 4.29; N, 2.91; B, 18.45. Calc. for C7H20B8Br2NRh (%): C, 17.98; H, 4.31; N, 3.00; B, 18.50. 2b, X = I, yield 193 mg (96%). 1H NMR (acetone-d6): δ=4.61 (s, 1H, NH), 3.47 (m, 2H, CH), 1.25 (s, 9H, tBu). 11B{1H} NMR (CDCl3): δ = − 3.4 (3B), − 12.5 (2B), − 15.7 (2B), − 17.5 (1B). Found (%): C, 15.03; H, 3.49; N, 2.49; B, 15.37. Calc. for C7H20B8I2NRh (%): C, 14.97; H, 3.59; N, 2.49; B, 15.40. Dichloromethane (2 ml) was added to a mixture of complex 2b (30 mg, 0.03 mmol) and TlBF4 (15 mg, 0.05 mmol). The reaction mixture was stirred overnight. The precipitate of TlI was filtered off. The solvent was removed in vacuo and the residue repricipitated from CH2Cl2 by petroleum ether. Yield 27 mg (93%) of [3]BF4 as a brown solid. 1H NMR (acetone-d6): δ = 5.11 (s, 1H, NH), 3.69 (s, 2H, CH), 1.32 (s, 9H, tBu). 11B{1H} NMR (acetone-d6): δ=−0.9 (1B, BF4),−2.1 (4B), − 6.9 (2B), − 9.2 (2B), − 15.7 (8B). Found (%): C, 15.39; H, 3.71; N, 2.51; B, 16.38. Calc. for C14H40B17F4I3N2Rh2 (%): C, 15.53; H, 3.72; N, 2.59; B, 16.97. Acetonitrile (2 ml) was added to a mixture of complex 2a (47 mg, 0.05 mmol) and Tl[Tl(η-7,8–C2B9H11)] (64 mg, 0.12 mmol). The reaction mixture was stirred overnight. The solvent was removed in vacuo. The residue was dissolved in CH2Cl2 and eluted through a layer (5 cm) of silica gel by the same solvent. The volume of the filtrate was reduced to ca. 0.5 ml in vacuo. Addition of petroleum ether (10 ml) precipitated 4 as a white solid, which was filtered off and dried in vacuo. Yield 20 mg (45%). 1H NMR (CDCl3): δ = 4.27 (s, 2 H, CH), 2.81 (s, 2 H, CH), 1.31 (s, 9 H, tBu). 11B{1H} NMR (CDCl3): δ = 8.4 (2B),− 3.3 (2B),− 5.0 (4B),− 12.0 (2B), − 14.0 (4B),− 19.0 (2B),− 21.2 (1B). Found (%): C, 24.38; H, 7.14; N, 3.05; B, 41.93. Calc. for C9H31B17NRh (%): C, 24.56; H, 7.10; N, 3.18; B, 41.77. Crystals of 2a,b were grown up by slow diffusion in a two-layer system: a solution of complex in CH2Cl2/petroleum ether. Crystal data for 2a: C14H40B16Br4N2Rh2, monoclinic, space group P21/c, a=13.9730(10) Å, b=12.5361(9) Å, c=17.8337(13) Å, β=94.2340(10)° V=3115.3(4) Å3, Z=4, dcalc =1.993 g cm− 3, μ=6.203 mm− 1, crystal size 0.45×0.35×0.20 mm, F(000)=1792, Tmin/Tmax 0.083/0.285, R1=0.0334 (from 5613 unique reflections with IN 2σ(I)) and wR2=0.0763 (from all 7420 unique reflections). Crystal data for 2b: C14H40B16I4N2Rh2, monoclinic, space group P21/n, a=15.4009(9) Å, b=6.5682(4) Å, c=17.1162(10) Å, β=112.1790(10)° V=1603.30 (16) Å 3 , Z = 2, d c a l c = 2.326 g cm − 3 , μ = 4.894 mm − 1 , crystal size 0.50×0.30×0.05 mm, F(000)=1040, Tmin/Tmax 0.187/0.783, R1=0.0448 (from 2665 unique reflections with IN 2σ(I)) and wR2=0.1045 (from all 3025 unique reflections). Single-crystal X-ray diffraction experiments were carried out with a Bruker SMART 1000 CCD area detector, using graphite monochromated Mo-Kα radiation (λ=0.71073 Å). The structures were solved by direct method and refined by the full-matrix least-squares against F2 in anisotropic approximation (for nonhydrogen atoms). The hydrogen atoms of the BH groups were found in the difference Fourier synthesis, and the positions of other hydrogen atoms were calculated. All hydrogen atoms were refined in isotropic approximation in riding model with the Uiso(H) parameters equal to 1.5 Ueq(Ci) for methyl groups and to 1.2 Ueq (Cii) and 1.2 Ueq(Bi) for other atoms, were Ueq(B) and Ueq(C) are the equivalent thermal parameters of the atoms to which the corresponding H atoms are bound. All calculations were performed using the SHELXTL software: G. M. Sheldrick, SHELXTL, Version 5.10, Bruker AXS Inc., Madison, WI, USA, 1998. a M.R. Churchill, S.A. Julis, F.J. Rotella, Inorg. Chem. 16 (1977) 1137; b M.R. Churchill, S.A. Julis, Inorg. Chem. 17 (1978) 3011; c M.R. Churchill, S.A. Julis, Inorg. Chem. 18 (1979) 2918. G. Ferguson, T.R. Spalding, P.A. McEneaney, Acta Cryst. C51 (1995) 1501. E.V. Mutseneck, D.S. Perekalin, J. Holub, K.A. Lyssenko, P.V. Petrovskii, B. Štíbr, A.R. Kudinov, Eur. J. Inorg. Chem. (2006) 1737.