51
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Zheng F, Xie Z. Reaction of o-carboranes with sterically demanding N-heterocyclic carbene: synthesis and structural characterization of 1 : 1 adducts. Dalton Trans 2012; 41:12907-14. [DOI: 10.1039/c2dt31765f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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52
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Tiwari R, Toppino A, Agarwal HK, Huo T, Byun Y, Gallucci J, Hasabelnaby S, Khalil A, Goudah A, Baiocchi RA, Darby MV, Barth RF, Tjarks W. Synthesis, biological evaluation, and radioiodination of halogenated closo-carboranylthymidine analogues. Inorg Chem 2011; 51:629-39. [PMID: 22175713 DOI: 10.1021/ic202150b] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The synthesis and initial biological evaluation of 3-carboranylthymidine analogues (3CTAs) that are (radio)halogenated at the closo-carborane cluster are described. Radiohalogenated 3CTAs have the potential to be used in the radiotherapy and imaging of cancer because they may be selectively entrapped in tumor cells through monophosphorylation by human thymidine kinase 1 (hTK1). Two strategies for the synthesis of a (127)I-labeled form of a specific 3CTA, previously designated as N5, are described: (1) direct iodination of N5 with iodine monochloride and aluminum chloride to obtain N5-(127)I and (2) initial monoiodination of o-carborane to 9-iodo-o-carborane followed by its functionalization to N5-(127)I. The former strategy produced N5-(127)I in low yields along with di-, tri-, and tetraiodinated N5 as well as decomposition products, whereas the latter method produced only N5-(127)I in high yields. N5-(127)I was subjected to nucleophilic halogen- and isotope-exchange reactions using Na(79/81)Br and Na(125)I, respectively, in the presence of Herrmann's catalyst to obtain N5-(79/81)Br and N5-(125)I, respectively. Two intermediate products formed using the second strategy, 1-(tert-butyldimethylsilyl)-9-iodo-o-carborane and 1-(tert-butyldimethylsilyl)-12-iodo-o-carborane, were subjected to X-ray diffraction studies to confirm that substitution at a single carbon atom of 9-iodo-o-carborane resulted in the formation of two structural isomers. To the best of our knowledge, this is the first report of halogen- and isotope-exchange reactions of B-halocarboranes that have been conjugated to a complex biomolecule. Human TK1 phosphorylation rates of N5, N5-(127)I, and N5-(79/81)Br ranged from 38.0% to 29.6% relative to that of thymidine, the endogenous hTK1 substrate. The in vitro uptake of N5, N5-(127)I, and N5-(79/81)Br in L929 TK1(+) cells was 2.0, 1.8, and 1.4 times greater than that in L929 TK1(-) cells.
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Affiliation(s)
- Rohit Tiwari
- Division of Medicinal Chemistry & Pharmacognosy, The Ohio State University, 500 West 12th Avenue, Columbus, Ohio 43210, USA
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Scholz M, Hey-Hawkins E. Carbaboranes as pharmacophores: properties, synthesis, and application strategies. Chem Rev 2011; 111:7035-62. [PMID: 21780840 DOI: 10.1021/cr200038x] [Citation(s) in RCA: 575] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Matthias Scholz
- Institut für Anorganische Chemie der Universität Leipzig, Germany
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54
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Rudakov DA, Kurman PV, Potkin VI. Synthesis and deborination of polyhalo-substituted ortho-carboranes. RUSS J GEN CHEM+ 2011. [DOI: 10.1134/s1070363211060107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Dash BP, Satapathy R, Gaillard ER, Norton KM, Maguire JA, Chug N, Hosmane NS. Enhanced π-Conjugation and Emission via Icosahedral Carboranes: Synthetic and Spectroscopic Investigation. Inorg Chem 2011; 50:5485-93. [DOI: 10.1021/ic200010q] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Barada Prasanna Dash
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, United States
| | - Rashmirekha Satapathy
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, United States
| | - Elizabeth R. Gaillard
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, United States
| | - Kathleen M. Norton
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, United States
| | - John A. Maguire
- Department of Chemistry, Southern Methodist University, Dallas, Texas 75275-0314, United States
| | - Neha Chug
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, United States
| | - Narayan S. Hosmane
- Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115-2862, United States
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El-Zaria ME, Arii H, Nakamura H. m-Carborane-based chiral NBN pincer-metal complexes: synthesis, structure, and application in asymmetric catalysis. Inorg Chem 2011; 50:4149-61. [PMID: 21438543 DOI: 10.1021/ic2002095] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have succeeded in synthesizing m-carborane-based chiral NBN-pincer ligands, 1,7-bis(oxazolinyl)-1,7-dicarba-closo-dodecaborane (Carbox) (7-9). The combination of bis(hydroxyamides) and 3 equiv of diethylaminosulfur trifluoride (DAST) is a key step for cyclization to form oxazoline rings in excellent yields. X-ray crystal structures of these ligands confirmed three donor sites, one central B and two flanking N atoms in fixed positions. The electrophilic halogenation of the Carbox pincer ligands with iodine and a catalytic amount of Lewis acid led to ring-opening of the oxazolines and afforded bis(haloamides) (13 and 14). The air- and moisture-stable Carbox pincer complexes of rhodium(III), nickel(II), and palladium(II) were synthesized by the oxidative addition of RhCl(3)·3H(2)O, Ni(COD)(2), and Pd(CH(3)CN)(4)[BF(4)](2) to the Carbox pincer ligands (7-9), respectively. The catalytic activity of the rhodium(III) complexes (18-20) was examined for the asymmetric conjugate reduction of α,β-unsaturated esters and reductive aldol reaction. Among these catalysts, [(S,S)-Carbox-iPr]Rh(OAc)(2)·H(2)O (18) showed the highest enantioselective catalytic ability for both asymmetric conjugate reduction and reductive aldol reaction.
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Affiliation(s)
- Mohamed E El-Zaria
- Department of Chemistry, Faculty of Science, Gakushuin University, 1-5-1 Mejiro, Tokyo 171-8588, Japan
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57
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Sevryugina Y, Julius RL, Hawthorne MF. Novel Approach to Aminocarboranes by Mild Amidation of Selected Iodo-carboranes. Inorg Chem 2010; 49:10627-34. [DOI: 10.1021/ic101620h] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Yulia Sevryugina
- International Institute of Nano and Molecular Medicine, School of Medicine, University of Missouri, 1514 Research Park Drive, Columbia, Missouri 65211-3450, United States
| | - Richard L. Julius
- International Institute of Nano and Molecular Medicine, School of Medicine, University of Missouri, 1514 Research Park Drive, Columbia, Missouri 65211-3450, United States
| | - M. Frederick Hawthorne
- International Institute of Nano and Molecular Medicine, School of Medicine, University of Missouri, 1514 Research Park Drive, Columbia, Missouri 65211-3450, United States
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58
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Qiu Z, Deng L, Chan HS, Xie Z. Synthesis and Structural Characterization of Group 10 Metal−Carboryne Complexes. Organometallics 2010. [DOI: 10.1021/om100669x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zaozao Qiu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China
| | - Liang Deng
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China
| | - Hoi-Shan Chan
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China
| | - Zuowei Xie
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, People's Republic of China
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin, People's Republic of China
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59
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Spokoyny A, Li T, Farha O, Machan C, She C, Stern C, Marks T, Hupp J, Mirkin C. Electronic Tuning of Nickel-Based Bis(dicarbollide) Redox Shuttles in Dye-Sensitized Solar Cells. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201002181] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Spokoyny A, Li T, Farha O, Machan C, She C, Stern C, Marks T, Hupp J, Mirkin C. Electronic Tuning of Nickel-Based Bis(dicarbollide) Redox Shuttles in Dye-Sensitized Solar Cells. Angew Chem Int Ed Engl 2010; 49:5339-43. [DOI: 10.1002/anie.201002181] [Citation(s) in RCA: 104] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Himmelspach A, Finze M. Dicarba-closo-dodecaboranes with One and Two Ethynyl Groups Bonded to Boron. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000064] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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62
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Puga A, Teixidor F, Sillanpää R, Kivekäs R, Viñas C. Iodinatedortho-Carboranes as Versatile Building Blocks to Design Intermolecular Interactions in Crystal Lattices. Chemistry 2009; 15:9764-72. [DOI: 10.1002/chem.200900926] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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63
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Puga A, Teixidor F, Sillanpää R, Kivekäs R, Arca M, Barberà G, Viñas C. From Mono- to Poly-Substituted Frameworks: A Way of Tuning the Acidic Character of CcH ino-Carborane Derivatives. Chemistry 2009; 15:9755-63. [DOI: 10.1002/chem.200900925] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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64
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Streubel R, Özbolat-Schön A, Bode M, Daniels J, Schnakenburg G, Teixidor F, Vinas C, Vaca A, Pepiol A, Farràs P. Investigations on the Reactivity of Li/Cl Phosphinidenoid Tungsten Complexes toward Various Iodine Compounds. Organometallics 2009. [DOI: 10.1021/om900443v] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rainer Streubel
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Aysel Özbolat-Schön
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Maren Bode
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Jörg Daniels
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Gregor Schnakenburg
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Francesc Teixidor
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de la UAB, E-08193 Bellaterra, Spain
| | - Clara Vinas
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de la UAB, E-08193 Bellaterra, Spain
| | - Albert Vaca
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de la UAB, E-08193 Bellaterra, Spain
| | - Ariadna Pepiol
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de la UAB, E-08193 Bellaterra, Spain
| | - Pau Farràs
- Institut de Ciència de Materials de Barcelona (CSIC), Campus de la UAB, E-08193 Bellaterra, Spain
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65
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66
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Barberà G, Vaca A, Teixidor F, Sillanpää R, Kivekäs R, Viñas C. Designed Synthesis of New ortho-Carborane Derivatives: from Mono- to Polysubstituted Frameworks. Inorg Chem 2008; 47:7309-16. [DOI: 10.1021/ic800362z] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gemma Barberà
- Institut de Ciencia de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Spain, Department of Chemistry, University of Jyväskylä, 40351 Jyväkylä, Finland, and Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Albert Vaca
- Institut de Ciencia de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Spain, Department of Chemistry, University of Jyväskylä, 40351 Jyväkylä, Finland, and Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Francesc Teixidor
- Institut de Ciencia de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Spain, Department of Chemistry, University of Jyväskylä, 40351 Jyväkylä, Finland, and Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Reijo Sillanpää
- Institut de Ciencia de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Spain, Department of Chemistry, University of Jyväskylä, 40351 Jyväkylä, Finland, and Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Raikko Kivekäs
- Institut de Ciencia de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Spain, Department of Chemistry, University of Jyväskylä, 40351 Jyväkylä, Finland, and Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
| | - Clara Viñas
- Institut de Ciencia de Materials de Barcelona (CSIC) Campus UAB, 08193 Bellaterra, Spain, Department of Chemistry, University of Jyväskylä, 40351 Jyväkylä, Finland, and Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
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67
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Teixidor F, Barberà G, Vaca A, Kivekäs R, Sillanpää R, Oliva J, Viñas C. Are Methyl Groups Electron-Donating or Electron-Withdrawing in Boron Clusters? Permethylation ofo-Carborane. J Am Chem Soc 2005; 127:10158-9. [PMID: 16028913 DOI: 10.1021/ja052981r] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
That methyl groups attached to carbon atoms are electron donors must not be generally assumed. In boron clusters, Me groups on boron are electron withdrawing. At the B3LYP/6-31G* level of theory, it has been proven that the Mulliken charge on each boron after substitution of -H by -Me increases by +0.18 unit. This leads to a high build-up of positive charge upon permethylation, then hampering it. Experimentally, this is proven by the synthesis of 9-I0.707H0.293-12-Cl0.566H0.434-3,4,5,6,7,8,10,11-Me8-1,2-C2B10H2, in which positions 9 and 12 were first methylated and then attacked by nucleophiles. This is substantiated by the synthesis of 3,6,8,9,10,12-Me6-1,2-C2B10H6 under the same experimental conditions but with time control.
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Affiliation(s)
- Francesc Teixidor
- Institut de Ciència de Materials de Barcelona (CSIC), Campus U.A.B., E-08193 Bellaterra, Spain
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Robertson S, Ellis D, McGrath TD, Rosair GM, Welch AJ. Synthesis and characterisation of labelled diphenylcarboranes. Polyhedron 2003. [DOI: 10.1016/s0277-5387(03)00103-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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70
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Tolmachev V, Sjöberg S. Polyhedral Boron Compounds as Potential Linkers for Attachment of Radiohalogens to Targeting Proteins and Peptides. A Review. ACTA ACUST UNITED AC 2002. [DOI: 10.1135/cccc20020913] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Polyhedral boron clusters (PBC) are three-dimensional inorganic aromatic systems. Some of them can easily be halogenated, and the halogen-boron bond in such systems is very strong. We consider the use of PBC as linkers for attachment of radioactive halogen isotopes to tumor-targeting proteins and peptides. In this review the major preconditions for such applications, such as biological considerations, knowledge concerning coupling chemistry and radiolabeling of PBC, are described. A review with 90 references.
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71
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Allis DG, Spencer JT. Polyhedral-based nonlinear optical materials. 2. Theoretical investigation of some new high nonlinear optical response compounds involving polyhedral bridges with charged aromatic donors and acceptors. Inorg Chem 2001; 40:3373-80. [PMID: 11421682 DOI: 10.1021/ic0007761] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A theoretical study of several new classes of polyhedral-based molecules has shown that these species display large calculated nonlinear optical responses. These new classes of molecules are based on charged aromatic subunits connected through polyhedral cluster bridges, such as closo-[1-(C(7)H(6))-12-(C(5)Me(4))C(2)B(10)H(10)]. These compounds show calculated first hyperpolarizabilities (beta) ranging from 6.5 to 8413.9 x 10(-30) cm(5) esu(-1). A basis for understanding the origin of these large responses is proposed based on the two-state model and consideration of the orbital and electronic features of the molecules. In general, the highest occupied molecular orbitals for these species are localized on the aromatic donor rings, such as the cyclopentadienyl system, while the lowest unoccupied molecular orbitals are largely on the aromatic acceptor rings, such as the tropylium system. The electronic properties of these polyhedral-based systems appear to be significantly different from the analogous organic [5.6.7]quinarene system (tropyliumcyclopentadienylbenzene). The organic quinarene appears to behave as a completely electron-delocalized system over all three rings while the polyhedral-based compounds can best be described as consisting of two relatively independent, highly polarized regions.
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Affiliation(s)
- D G Allis
- Department of Chemistry and W. M. Keck Center for Molecular Electronics, Center for Science and Technology, Syracuse University, Syracuse, New York 13244, USA
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72
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Cr&acaron;ciun L, Custelcean R. Syntheses and Crystal Structures of 9-Acetyl- and 9-Cyano-1,2-dicarbadodecaborane: Supramolecular Association in Carboranyl C-H Hydrogen-Bonded alpha-Networks. Inorg Chem 1999; 38:4916-4919. [PMID: 11671228 DOI: 10.1021/ic9904889] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Liliana Cr&acaron;ciun
- Departments of Chemistry, Princeton University, Princeton, New Jersey 08544-1009, and Michigan State University, East Lansing, Michigan 48824-1322
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73
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Schleyer PVR, Najafian K. Stability and Three-Dimensional Aromaticity of closo-Monocarbaborane Anions, CB(n)()(-)(1)H(n)(-), and closo-Dicarboranes, C(2)B(n)()(-)(2)H(n)(). Inorg Chem 1998; 37:3454-3470. [PMID: 11670428 DOI: 10.1021/ic980110v] [Citation(s) in RCA: 219] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Comprehensive ab initio calculations RMP2(fc)/6-31G on the closo-monocarbaboranes, CB(n)()(-)(1)H(n)()(-) (n = 5-12), and the closo-dicarboranes, C(2)B(n)()(-)(2)H(n)() (n = 5-12), show that the relative energies of all the positional isomers agree with the qualitative connectivity considerations of Williams and with the topological charge stabilization rule of Gimarc. The reaction energies (DeltaH) of the most stable positional isomers, 1-CB(4)H(5)(-), CB(5)H(6)(-), 2-CB(6)H(7)(-), 1-CB(7)H(8)(-), 5-CB(8)H(9)(-), 1-CB(9)H(10)(-), 2-CB(10)H(11)(-), CB(11)H(12)(-), as well as 1,5-C(2)B(3)H(5), 1,6-C(2)B(4)H(6), 2,4-C(2)B(5)H(7), 1,7-C(2)B(6)H(8), 4,5-C(2)B(7)H(9), 1,10-C(2)B(8)H(10), 2,3-C(2)B(9)H(11), and 1,12-C(2)B(10)H(12) (computed using the equations, CBH(2)(-) + (n - 1)BH(increment) --> CB(n)()H(n)()(+1)(-) (n = 4-11) and C(2)H(2) + nBH(increment) --> C(2)B(n)()H(n)()(+2) (n = 3-10)), show that the stabilities of closo-CB(n)()(-)(1)H(n)()(-) and of closo-C(2)B(n)()(-)(2)H(n)() generally increase with increasing cluster size from 5 to 12 vertexes. This is a characteristic of three-dimensional aromaticity. There are variations in stabilities of individual closo-CB(n)()(-)(1)H(n)()(-) and closo-C(2)B(n)()(-)(2)H(n)() species, but these show quite similar trends. Moreover, there is rough additivity for each carbon replacement. The rather large nucleus independent chemical shifts (NICS) and the magnetic susceptibilities (chi), which correspond well with one another, also show all closo-CB(n)()(-)(1)H(n)()(-) and closo-C(2)B(n)()(-)(2)H(n)() species to exhibit "three-dimensional aromaticity". However, the aromaticity ordering based on these magnetic properties does not always agree with the relative stabilities of positional isomers of the same cluster, when other effects such as connectivity and charge considerations are important.
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Affiliation(s)
- Paul von Ragué Schleyer
- Institut für Organische Chemie der Universität Erlangen-Nürnberg, Henkstrasse 42, D-91054 Erlangen, Germany, and Department of Chemistry, University of Georgia, Athens, Georgia 30602
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Jemmis ED, Kiran B, Coffey D. Ab Initio Studies on Disubstituted closo-Icosahedral Heteroboranes, X2B10H10 [X = CH, SiH, N, P, and Sb]. ACTA ACUST UNITED AC 1997. [DOI: 10.1002/cber.19971300818] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Jemmis ED, Kiran B. Structure and Bonding in B10X2H10 (X = C and Si). The Kinky Surface of 1,2-Dehydro-o-disilaborane. J Am Chem Soc 1997. [DOI: 10.1021/ja964385q] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Boggavarapu Kiran
- School of Chemistry, University of Hyderabad Hyderabad 500046, India
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Usyatinsky AY, Budkina KV, Petrovskii PV, Bregadze VI. Mercuration ofB(9)-substitutedmeta- andortho-carboranes. Russ Chem Bull 1995. [DOI: 10.1007/bf00698511] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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77
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Jones M. Carboranylcarbenes. Russ Chem Bull 1993. [DOI: 10.1007/bf00703988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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