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Electronic structure and spectroscopy of the cycloheptatrienyl molybdenum halide complexes [MoBrL2(η-C7H7)]+ (L2= 2CO, n= 0; L2= 2,2′-bipyridyl, n= 0 or 1). Polyhedron 2015. [DOI: 10.1016/j.poly.2014.05.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Lancashire HN, Brown NJ, Carthy L, Collison D, Fitzgerald EC, Edge R, Helliwell M, Holden M, Low PJ, McDouall JJW, Whiteley MW. Synthesis, spectroscopy and electronic structure of the vinylidene and alkynyl complexes [W(CCHR)(dppe)(η-C7H7)]+and [W(CCR)(dppe)(η-C7H7)]n+(n = 0 or 1). Dalton Trans 2011; 40:1267-78. [DOI: 10.1039/c0dt01150a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Grime RW, Helliwell M, Hussain ZI, Lancashire HN, Mason CR, McDouall JJW, Mydlowski CM, Whiteley MW. Metallacumulenylidene Complexes in the Cycloheptatrienyl Molybdenum Series [Mo{(C)n═CR2}L2(η-C7H7)]+ (n = 0−2; L2 = P-Donor Ligand). X-ray Crystal Structures of [Mo{C═C(H)Ph}{P(OMe)3}2(η-C7H7)][BF4] and [Mo(C═C═CPh2)(dppe)(η-C7H7)][PF6] and DFT Investigation of Cumulenylidene Ligand Orientations. Organometallics 2008. [DOI: 10.1021/om700920t] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Richard W. Grime
- School of Chemistry, University of Manchester, Manchester M13 9PL, U.K
| | | | - Zaffar I. Hussain
- School of Chemistry, University of Manchester, Manchester M13 9PL, U.K
| | | | | | | | | | - Mark W. Whiteley
- School of Chemistry, University of Manchester, Manchester M13 9PL, U.K
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Petrovic D, Hrib CG, Randoll S, Jones PG, Tamm M. Synthesis and Reactivity of 16-Electron Cycloheptatrienyl-Molybdenum(0) Complexes with Bis(imidazolin-2-imine) Ligands. Organometallics 2008. [DOI: 10.1021/om700953u] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dejan Petrovic
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina, Hagenring 30, 38106 Braunschweig, Germany
| | - Cristian G. Hrib
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina, Hagenring 30, 38106 Braunschweig, Germany
| | - Sören Randoll
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina, Hagenring 30, 38106 Braunschweig, Germany
| | - Peter G. Jones
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina, Hagenring 30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina, Hagenring 30, 38106 Braunschweig, Germany
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Synthesis of the sterically crowded cycloheptatrienyl complexes [M(CO)(PPh3)2(η-C7H7)]+ (M=Mo or W): X-ray crystal structures of [W(CO)(PPh3)2(η-C7H7)][BF4] and [W(CO)2(PPh3)(η-C7H7)][BF4]·CH2Cl2. J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2006.01.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Tamm M, Bannenberg T, Fröhlich R, Grimme S, Gerenkamp M. Mono- and dinuclear molybdenum complexes with sterically demanding cycloheptatrienyl ligands. Dalton Trans 2004:482-91. [PMID: 15252558 DOI: 10.1039/b314347c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sterically demanding cycloheptatrienylium (tropylium) salts of the type (1,3,5-C7H4R3)BF4 [R = t-Bu, (3a)BF4; R = SiMe3, (3b)BF4] have been prepared from the corresponding 1,3,5-trisubstituted benzene derivatives 1 by ring expansion with diazomethane followed by hydride abstraction with triphenylcarbenium tetrafluoroborate, (Ph3C)BF4. Complexation can be achieved by arene exchange and Mo(CO)3 group transfer employing [(eta6-p-xylene)Mo(CO)3] (4) to yield the cationic complexes (5)BF4. In refluxing mesitylene, [(eta7-C7H4t-Bu3)Mo(CO)3]BF4, (5a)BF4, undergoes CO substitution to furnish the mesitylene sandwich complex (6a)BF4. A cyclic voltammetric study reveals that this complex exhibits a reversible one-electron oxidation to the dicationic 17e complex 6a2+, which can also be accessed by chemical oxidation with AgBF4. On the contrary, the reduction of 6a+ is irreversible and does not yield a stable 19e complex 6a. To study the fate of the reduced 19e form, (5a)BF4 was treated with Na2Hg to diastereoselectively afford the C-C coupled bicycloheptatriene complex 7a. Paramagnetic, dinuclear complexes of the type [(eta7-C7H4R3)Mo(mu-Cl)3Mo(eta7-C7H4R3)] (8) have been obtained from the reaction of (5)BF4 with Me3SiCl. These can be regarded as mixed-valence Mo(0)/Mo(+I) compounds with a metal-metal bond order of 0.5. Cyclic voltammetric studies reveal that both complexes 8a and 8b undergo reversible one-electron oxidation as well as reduction. Treatment with one equivalent of ferrocenium hexafluorophosphate leads to removal of the unpaired electron and formation of the diamagnetic complexes (8)PF6. Theoretical DFT calculations have been carried out to further elucidate the bonding in these systems. In addition, the X-ray crystal structures of (5b)BF4, (6a)BF4 x CH2Cl2, (6a)(BF4)2 x (acetone)2, 7a x CH2Cl2, 8a x 0.5C6H14, and (8a)PF6 x Et2O are reported.
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Affiliation(s)
- Matthias Tamm
- Anorganisch-chemisches Institut, Lehrstuhl für Anorganische Chemie,Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
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Tamm M, Dreßel B, Lügger T, Fröhlich R, Grimme S. Chelate Complexes of Functionalized Cycloheptatrienyl Ligands: Molybdenum Complexes with Linked Cycloheptatrienyl-Phosphane Ligands and Their Use in Catalytic Carbon−Carbon Bond Formation. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200390140] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Brunner H, Klankermayer J, Zabel M. Synthesis, Stereochemistry and Molecular Structures of Chiral-at-Metal (Cycloheptatrienyl)molybdenum Complexes Containing the Diphosphane Prophos. Eur J Inorg Chem 2002. [DOI: 10.1002/1099-0682(200209)2002:9<2494::aid-ejic2494>3.0.co;2-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Tamm M, Bannenberg T, Dressel B, Fröhlich R, Holst C. Molybdenum complexes with linked cycloheptatrienyl-phenolate ligands. Inorg Chem 2002; 41:47-59. [PMID: 11782143 DOI: 10.1021/ic010902g] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The tropylium salt (2-hydroxy-3,5-dimethylphenyl)cycloheptatrienylium tetrafluoroborate (3) has been synthesized in three steps from THP-protected 2,4-dimethylphenol and tropylium tetrafluoroborate, (C(7)H(7))BF(4). In CH(2)Cl(2) solution, the unexpected formation of tricyclic 2,4-dimethylbenzo[b]cyclohepta[d]furanylium tetrafluoroborate (5) has been observed, which must have formed from 3 by loss of H(2). 5 was characterized by an X-ray crystal structure determination and could independently be synthesized by treatment of 3 with NaHCO(3) to give 2,4-dimethylbenzo[b]cyclohepta[d]furan (4) followed by acidification with HBF(4).Et(2)O. The arene transfer reaction of 3 with [(eta-p-xylene)Mo(CO)(3)] furnished the cycloheptatrienyl complex [(HOC(6)H(2)Me(2)-eta(7)-C(7)H(6))Mo(CO)(3)]BF(4) (6), which could be converted into the chiral chelate complexes [(OC6H2Me2-eta7-C7H6)Mo(CO)(PR3)](9a, R = Ph; 9b, R = c-C(6)H(11); 9c, i-Pr) by subsequent treatment with NaI, PR(3), and NaH. The linked cycloheptatienyl-phenolate ligand in 9a could be protonated at the coordinated oxygen atom employing HBF(4).Et(2)O to yield [(HOC6H2Me2-eta7-C7H6)Mo(CO)(PPh3)]-BF4 (10). In 10, the appended phenol group is coordinated in a hemilabile fashion, which allowed the introduction of 2,6-dimethylphenyl isocyanide and CO and formation of complexes [(HOC(6)H(2)Me(2)-eta(7)-C(7)H(6))Mo(CO)(PPh(3))L]BF(4) (11, L = XyNC; 12, L = CO). On thermal reaction of [(HOC(6)H(2)Me(2)-eta(7)-C(7)H(6))Mo(CO)(2)I] (7) with dppe, the addition of the diphosphine was observed together with the simultaneous formation of the molydenum-oxygen bond to yield [(OC6H2Me2-eta3-C7H6)Mo(CO)2(dppe)] (13), in which the cycloheptatrienyl ring has reduced its hapticity from seven to three. The pseudooctahedral complex 13 exhibits an interesting fluxional behavior in solution, which has been studied by means of variable-temperature (31)P and (1)H NMR spectroscopy. A eta(3) --> eta(7) hapticity reversion could be achieved by UV irradiation of a solution of 13 in THF to give the electron-rich complex [(OC6H2Me2-eta7-C7H6)Mo(dppe)] (14). 14 was readily oxidized with ferrocenium hexafluorophosphate, and the resulting paramagnetic monocationic complex 15 has been studied by means of ESR spectroscopy and X-ray diffraction. In addition, the X-ray crystal structures of complexes 9a, 10.2CH(2)Cl(2), 12, and 13 are reported.
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Affiliation(s)
- Matthias Tamm
- Anorganisch-Chemisches Institut, Westfälische Wilhelms-Universität, Münster, Germany.
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Tamm M, Bannenberg T, Dressel B, Fröhlich R, Kunz D. Molybdenum Complexes with Sterically Demanding Cycloheptatrienyl Ligands. Organometallics 2001. [DOI: 10.1021/om000830l] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Synthesis and redox properties of the cycloheptatrienylmolybdenum complexes [MoX(N–N)(η-C7H7)]z+, (N–N=2,2′-bipyridine or 1,4-But2-1,3-diazabutadiene; z=0, X=Br or Me; z=1, X=NCMe, CNBut or CO). J Organomet Chem 1998. [DOI: 10.1016/s0022-328x(98)00708-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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12
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13
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Green MLH, Ng DKP, Wong HV. New η-cycloheptatrienyl tungsten compounds and the intercalation of [M(η-C7H7)(η-C5H4Me)](M = Mo or W) into ZrS2. ACTA ACUST UNITED AC 1993. [DOI: 10.1039/dt9930003213] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Green MLH, Ng DKP, Tovey RC. New synthetic pathways in η-cycloheptatrienyl molybdenum chemistry. ACTA ACUST UNITED AC 1992. [DOI: 10.1039/c39920000918] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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16
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