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Desolvation and Dehydrogenation of Solvated Magnesium Salts of Dodecahydrododecaborate: Relationship between Structure and Thermal Decomposition. Chemistry 2014; 20:7325-33. [DOI: 10.1002/chem.201303842] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 02/20/2014] [Indexed: 11/08/2022]
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Abstract
A dihydrogen bond (DHB) is an electrostatic interaction between a protonic hydrogen and a hydridic hydrogen. Over the past two decades, researchers have made significant progress in the identification and characterization of DHBs and their properties. In comparison with conventional hydrogen bonds (HBs), which have been widely used in catalysis, molecular recognition, crystal engineering, and supramolecular synthesis, chemists have only applied DHBs in very limited ways. Considering that DHBs and conventional HBs have comparable strength, DHBs could be more widely applied in chemistry. Over the past several years, we have explored the impact of DHBs on amine borane chemistry and the syntheses and characterization of amine boranes and ammoniated metal borohydrides for hydrogen storage. Through systematic computational and experimental investigations, we found that DHBs play a dominant role in dictating the reaction pathways (and thus different products) of amine boranes where oppositely charged hydrogens coexist for DHB formation. Through careful experiments, we observed, for the first time, a long-postulated reaction intermediate, ammonia diborane (AaDB), whose behavior is essential to mechanistic understanding of the formation of the diammoniate of diborane (DADB) in the reaction of ammonia (NH3) with tetrahydrofuran borane (THF·BH3). The formation of DADB has puzzled the boron chemistry community for decades. Mechanistic insight enabled us to develop facile syntheses of aminodiborane (ADB), ammonia borane (AB), DADB, and an inorganic butane analog NH3BH2NH2BH3 (DDAB). Our examples, together with those in the literature, reinforce the fact that DHB formation and subsequent molecular hydrogen elimination are a viable approach for creating new covalent bonds and synthesizing new materials. We also review the strong effects of DHBs on the stability of conformers and the hydrogen desorption temperatures of boron-nitrogen compounds. We hope that this Account will encourage further applications of DHBs in molecular recognition, host-guest chemistry, crystal engineering, supramolecular chemistry, molecular self-assembly, chemical kinetics, and the syntheses of new advanced materials.
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Synthesis, structural analysis, and thermal decomposition studies of [(NH3)2BH2]B3H8. RSC Adv 2013. [DOI: 10.1039/c3ra22836c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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New Syntheses and Structural Characterization of NH3BH2Cl and (BH2NH2)3 and Thermal Decomposition Behavior of NH3BH2Cl. Inorg Chem 2012; 51:13430-6. [DOI: 10.1021/ic302308v] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Structures of DMF solvated potassium and sodium salts of [Fe(CO)4]2− and [M2(CO)8]2− (M = Fe, Ru). J Organomet Chem 2012. [DOI: 10.1016/j.jorganchem.2012.07.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Corrigendum: Large-Scale and Facile Preparation of Pure Ammonia Borane through Displacement Reactions. Chemistry 2012. [DOI: 10.1002/chem.201203472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Large-Scale and Facile Preparation of Pure Ammonia Borane through Displacement Reactions. Chemistry 2012; 18:11994-9. [DOI: 10.1002/chem.201201342] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Indexed: 11/06/2022]
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A Convenient Synthesis and a NMR Study of the Diammoniate of Diborane. Chemistry 2012; 18:3490-2. [DOI: 10.1002/chem.201103693] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Indexed: 11/06/2022]
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Unusual Cationic Tris(Dimethylsulfide)-Substituted closo-Boranes: Preparation and Characterization of [1,7,9-(Me2S)3-B12H9] BF4 and [1,2,10-(Me2S)3-B10H7] BF4. Inorg Chem 2012; 51:2374-80. [PMID: 22309402 DOI: 10.1021/ic2023709] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Anti and gauche conformers of an inorganic butane analogue, NH3BH2NH2BH3. Chem Commun (Camb) 2012; 48:7943-5. [DOI: 10.1039/c2cc33621a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Experimental and Computational Study of the Formation Mechanism of the Diammoniate of Diborane: The Role of Dihydrogen Bonds. J Am Chem Soc 2011; 133:14172-5. [DOI: 10.1021/ja203648w] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ammonium octahydrotriborate (NH4B3H8): new synthesis, structure, and hydrolytic hydrogen release. Inorg Chem 2011; 50:3738-42. [PMID: 21405091 DOI: 10.1021/ic2000987] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A metathesis reaction between unsolvated NaB(3)H(8) and NH(4)Cl provides a simple and high-yield synthesis of NH(4)B(3)H(8). Structure determination through X-ray single crystal diffraction analysis reveals weak N-H(δ+)---H(δ-)-B interaction in NH(4)B(3)H(8) and strong N-H(δ+)---H(δ-)-B interaction in NH(4)B(3)H(8)·18-crown-6·THF adduct. Pyrolysis of NH(4)B(3)H(8) leads to the formation of hydrogen gas with appreciable amounts of other volatile boranes below 160 °C. Hydrolysis experiments show that upon addition of catalysts, NH(4)B(3)H(8) releases up to 7.5 materials wt % hydrogen.
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A Simple and Efficient Way to Synthesize Unsolvated Sodium Octahydrotriborate. Inorg Chem 2010; 49:8185-7. [DOI: 10.1021/ic101543v] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Facile Synthesis of Aminodiborane and Inorganic Butane Analogue NH3BH2NH2BH3. J Am Chem Soc 2010; 132:10658-9. [DOI: 10.1021/ja104938v] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Redetermination of di-μ-hydrido-hexa-hydridotetra-kis(tetra-hydro-furan)dialuminium(III)magnesium(II). Acta Crystallogr Sect E Struct Rep Online 2010; 66:m575. [PMID: 21579056 PMCID: PMC2979026 DOI: 10.1107/s1600536810014200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 04/18/2010] [Indexed: 05/26/2023]
Abstract
The structure of the title compound, [Mg(AlH4)2(C4H8O)4], has been redetermined at 150 K. The MgII ion is hexacoordinated to four tetrahydrofuran (THF) ligands, and two AlH4− anions through bridging H atoms. The Al—H distances are more precise compared to those previously determined [Nöth et al. (1995 ▶). Chem. Ber. 128, 999–1006; Fichtner & Fuhr (2002 ▶). J. Alloys Compd, 345, 386–396]. The molecule has twofold rotation symmetry.
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Li2B12H12·7NH3: a new ammine complex for ammonia storage or indirect hydrogen storage. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b923829h] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Intermolecular dihydrogen- and hydrogen-bonding interactions in diammoniumcloso-decahydrodecaborate sesquihydrate. Acta Crystallogr C 2009; 66:m1-3. [DOI: 10.1107/s0108270109040815] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 10/06/2009] [Indexed: 11/10/2022] Open
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β-Agostic Interactions in 15-Valence-Electron 9-BBN Hydroborate Half-Sandwich Titanium(III) Complexes. Organometallics 2009. [DOI: 10.1021/om8009014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Water-Free Rare Earth-Prussian Blue Type Analogues: Synthesis, Structure, Computational Analysis, and Magnetic Data of {LnIII(DMF)6FeIII(CN)6}∞ (Ln = Rare Earths Excluding Pm). Inorg Chem 2009; 48:5725-35. [PMID: 20507100 DOI: 10.1021/ic8022369] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Syntheses and Structures of Alkaline Earth−Transition Metal Bimetallic Complexes As Heterogeneous Hydrodechlorination Catalyst Precursors. Inorg Chem 2008; 48:325-30. [DOI: 10.1021/ic801912x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Novel one step preparation of silica supported Pd/Sr and Pd/Ba catalysts via an organometallic precursor: Application in hydrodechlorination and hydrogenation. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.molcata.2008.07.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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The Structure of Potassium and Tetramethylammonium Salts of the Cyclic Organohydroborate Anion [H
2
BC
8
H
14
]
–
with Different Solvent Ligands. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700836] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nature of “Hydrogen Bond” in the Diborane−Benzene Complex: Covalent, Electrostatic, or Dispersive? Inorg Chem 2007; 46:3956-9. [PMID: 17428045 DOI: 10.1021/ic061857l] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Motivated by the recent discovery of unusual "hydrogen bonding"-like interaction between a borane system and benzene molecules in a molecular crystal, we carried out quantum mechanical calculations on a model complex, diborane-benzene cluster. The aim is to understand the nature of this unique interaction, which is expected to play an essential role in this novel class of molecular crystals. As analyzed in the present study, the interaction between diborane and benzene is special in the following aspects: (1) this interaction is mostly dispersive; (2) the observed pseudodirectionality with one of the diborane bridge hydrogen directed toward the benzene centroid minimizes the van der Waals contact; and (3) in the "hydrogen bond" map, this interaction is located in a unique region, which is presently populated by a few known molecular complexes with very different chemical characteristics. It is anticipated that the results from the present analysis will provide meaningful guidance for molecular engineering with diborane-benzene as a building block and for stabilization of this and possible other hydrogen bonds by dispersive contributions.
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Lanthanide−Transition Metal Carbonyl Complexes: Condensation of Solvent-Separated Ion-Pair Compounds into Extended Structures. Inorg Chem 2006; 45:10115-25. [PMID: 17140217 DOI: 10.1021/ic060756k] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New solvent-separated ion-pair compounds and extended structures containing ytterbium(II)-transition metal isocarbonyl linkages were synthesized. [Yb(THF)6][M(CO)5]2 (1, M = Mn; 2, M = Re) were prepared via transmetalation reactions between Yb metal and Hg[M(CO)5]2 in THF. Reflux of 1 in Et2O afforded {Yb(THF)2(Et2O)2[(mu-CO)2Mn(CO)3]2}infinity (3) which is a sheet-layer structure. In ether solution, 3 is converted to {Yb(THF)4[(mu-CO)2Mn(CO)3]2}infinity (4) which has a linear structure. In both 3 and 4, ytterbium is 8-coordinated (distorted square antiprism geometry), four coordination sites occupied by molecules of solvent and four more by oxygen atoms of isocarbonyl linkages. The [Mn(CO)5]- anion has trigonal bipyramidal geometry and is linked to ytterbium through two equatorial carbonyls. The formation of two minor products, (THF)2Mn3(CO)10 (5) and [(THF)5Yb(mu-CO)Mn3(CO)13][Mn3(CO)14] (6), was observed during condensation of 1 into 3 and 4.
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A Stacking Interaction between a Bridging Hydrogen Atom and Aromatic π Density in then-B18H22–Benzene System. Chemistry 2006; 12:2571-8. [PMID: 16411258 DOI: 10.1002/chem.200501043] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The structures of n-B18H22 and of n-B18H22 x C6H6 were determined by single-crystal X-ray analysis at -60 degrees C. The geometry of the boron cluster itself does not seem to be appreciably affected by solvation. There does, however, appear to be an unusual interaction of a polyborane bridging hydrogen atom with the benzene pi system, giving rise to an extended stacked structure. The 1H{11B} spectrum of n-B18H22 in [D6]benzene differs from that in [D12]cyclohexane most noticeably in the bridging proton region. Upon moving from the aliphatic to the aromatic solvent, the greatest increase in shielding was for the signal corresponding to the bridge hydrogen atom that interacts with the pi system of benzene; the signal was shifted upfield by 0.49 ppm. Density functional theory calculations were performed on 1:1 and 2:1 complexes of the n-B18H22 unit with benzene.
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Europium(II) and Ytterbium(II) Cyclic Organohydroborates with Agostic Interactions. Inorg Chem 2005; 44:6052-61. [PMID: 16097825 DOI: 10.1021/ic050573i] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The divalent lanthanide bis((cyclooctane-1,5-diyl)dihydroborate) complexes {K(THF)4}2{Ln{(mu-H)2BC8H14}4} (Ln = Eu, 3; Yb, 4) were prepared by a metathesis reaction between (THF)(x)LnCl2 and K[H2BC8H14] in THF in a 1:4 molar ratio. Although the reaction ratios were varied between 1:3 and 1:6, complexes 3 and 4 were the only lanthanide 9-BBN hydroborates produced. Because of disorder of THF in crystals of 3 and 4, good single-crystal X-ray structural data could not be obtained. However, when the potassium cation was replaced by the tetramethylammonium cation or when MeTHF (2-methyltetrahydrofuran) was employed in place of THF, good quality crystals were obtained. Complexes [NMe4]2[Ln{(mu-H)2BC8H14}4] (Ln = Eu, 5; Yb, 6) were afforded by metathesis reactions of NMe4Cl with 3 and 4 in situ. On the basis of the single-crystal X-ray diffraction analysis, the four 9-BBN tetrahydroborate ligands are tetrahedrally arranged around the lanthanide cation in 5 and 6. The two structures differ in that one alpha-C-H bond from each of the four {(mu-H)2BC8H14}4 units exhibits an agostic interaction with Eu(II) in 5 but, in complex 6, only two of the alpha-C-H bonds form agostic interactions with Yb(II). Complexes {K(MeTHF)3}2{Ln{(mu-H)2BC8H14}4} (Ln = Eu, 7; Yb, 8) were produced by employing MeTHF in place of THF. The structures of 7 and 8 display connectivity between the anion {Ln{(mu-H)2BC8H14}4}2- and the cation {K(MeTHF)3}+, in which the potassium not only interacts directly with the hydrogens of the Ln-H-B bridged bonds but is also involved in agostic interactions with alpha-C-H bonds. By systematically examining the structures of complexes 3-8 and taking into account the previously reported complexes (THF)4Ln{(mu-H)2BC8H14}2 (Ln = Eu, 1; Yb, 2), it is concluded that Eu(II) appears to have a better ability to form agostic interactions than Yb(II) because of its larger size, even though Yb(II) has a higher positive charge density.
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Preparation and crystal structures of a series of titanium(III) 9-BBN hydroborate complexes containing Ti...H agostic interactions. Inorg Chem 2005; 44:4871-8. [PMID: 15962996 DOI: 10.1021/ic050422f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
9-BBN hydroborate complexes Ti{(mu-H)2BC8H14}3(THF)2 (1), Ti{(mu-H)2BC8H14}3(OEt2) (2), and [K(OEt2)4]-[Ti{(mu-H)2BC8H14}4] (4) were formed from the reaction of TiCl4 with K[H2BC8H14] in diethyl ether or THF. Ti{(mu-H)2BC8H14}3(PhNH2) (3) was isolated from the reaction of 2 with aniline in diethyl ether. In the formation of these complexes, Ti(IV) is reduced to Ti(III). The coordinated diethyl ether in 2 can be displaced by the stronger bases THF and aniline, to form 1 and 3, respectively. All of the compounds were characterized by single-crystal X-ray diffraction analysis. In complex 1, which contains two coordinated THF ligands, the titanium possesses a 17 electron configuration and there is no evidence for agostic interaction. Complexes 2 and 3 contain only one coordinated ether or aniline ligand, and the titanium possesses a 15 electron configuration. In these compounds, a C-H hydrogen on an alpha carbon on the BC8H14 unit of a 9-BBN hydroborate ligand forms an agostic interaction with the titanium. Criteria for assessing the existence of agostic interactions are discussed. As the potassium salt, the anion of complex 4 is more stable than the complexes 1-3. Organometallic anions of the type [ML4]- for titanium(III) are rare.
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Abstract
The complex Zr(9-BBN)4 [9-BBN = (mu-H)2BC8H14] has been synthesized via the reaction of K(9-BBN) with ZrCl4 in diethyl ether. The structure of the title compound has been determined by X-ray and neutron single-crystal diffraction techniques. Each 9-BBN ligand is coordinated to the Zr atom via two B-H-Zr bridges, and these metal-ligand bonding interactions are further augmented by three prominent C-H...Zr agostic interactions. Average molecular parameters derived from the neutron analysis: Zr-H = 2.051(8) A, B-H = 1.286(7) A, Zr...B = 2.409(6) A, Zr-H-B = 87.7(4) degrees , H-Zr-H = 58.9(3) degrees . The Zr...H distances corresponding to the three C-H...Zr agostic interactions are 2.424(7), 2.663(8), and 2.551(7) A. The fourth potential C-H...Zr interaction has a Zr...H distance [3.146(7) A] that is too long to be considered in the agostic range. Single-crystal X-ray diffraction data were collected on an Enraf-Nonius Kappa CCD diffraction system, and neutron diffraction data were collected on the quasi-Laue diffractometer VIVALDI at the Institut Laue-Langevin; the final agreement factor for the neutron analysis is 6.52% for 2557 reflections with I > 2sigma(I).
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Two Distinct Ln(III)−Cu(I) Cyanide Extended Arrays: Structures and Synthetic Methodology for Inclusion and Layer Complexes. Inorg Chem 2005; 44:282-92. [PMID: 15651874 DOI: 10.1021/ic040113+] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Encapsulation complexes formulated as {[La(DMF)(9)](2)[Cu(12)(CN)(18)].2DMF}(infinity), 1, and {[Ln(DMF)(8)][Cu(6)(CN)(9)].2DMF}(infinity) (Ln = Eu, 2; Gd, 3; Er, 4) were obtained from the one step reaction of LnCl(3) (Ln = La, Eu, Gd, Er) with CuCN and KCN in DMF. They consist of a three-dimensional Cu-CN anionic array with pockets occupied by the cation, [Ln(DMF)(x)](3+) (x = 8, 9). These complexes are believed to be the first examples of encapsulated Ln(3+) cations, and the zeolite-like anionic network is unique. A two step procedure that employs the same components generates the layer structure {Ln(DMF)(4)Cu(2)(CN)(5)}(infinity) (Ln = La, 5; Gd, 6; Er, 7) in which the five-membered ring repeating unit has Cu-CN-Ln and Cu-CN-Cu linkages which are also without precedent. Encapsulation complexes can also be prepared from CuCl, reacting with LnCl(3) and KCN. The crystal structure of {K(DMF)(2)Cu(CN)(2)}(infinity) (8) provides insight into the proposed reaction pathways for forming these two different structural types.
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The application of {(DMF)10Yb2[TM(CN)4]3}∞ (TM = Ni, Pd) supported on silica to promote gas phase phenol hydrogenation. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2003.11.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Effect of Solvent in the Reaction of Cp2ZrH{(μ-H)2BR2} (R2 = C4H8, C8H14) with B(C6F5)3: Formation of [HB(C6F5)3]- Salts of the Unsupported Hydrogen-Bridged Cations [(μ-H){Cp2Zr(μ-H)2BR2}2]+ (R2 = C4H8, C8H14) and [Cp2Zr(OEt2)X]+ (X = OEt, {(μ-H)2BC8H14}). Organometallics 2004. [DOI: 10.1021/om030692a] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Europium(II) and Ytterbium(II) Cyclic Organohydroborates: An Europium(II) Complex with an Agostic Interaction. Inorg Chem 2003; 43:692-8. [PMID: 14731031 DOI: 10.1021/ic030249s] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lanthanide bis((cyclooctane-1,5-diyl)dihydroborate) complexes (THF)(4)Ln[(micro-H)(2)BC(8)H(14)](2) (Ln = Eu, 1; Yb, 2) were synthesized by a metathesis reaction between (THF)(x)()LnCl(2) and K[H(2)BC(8)H(14)] in THF in a 1:2 molar ratio. Attempts to prepare the monosubstituted lanthanide cyclic organohydroborates (THF)(x)LnCl[(micro-H)(2)BC(8)H(14)] were unsuccessful. On the basis of the molecular structure and IR spectrum of 1, there is an agostic interaction between Eu(II) and one of the alpha-C-H hydrogens from the [(micro-H)(2)BC(8)H(14)] unit. No such interaction was observed for 2. The coordinated THF in 1 and 2 can be removed under dynamic vacuum, but the solvent ligands remain bound to Yb when 2 is directly dissolved in Et(2)O or toluene. In strong Lewis basic solvents, such as pyridine or CH(3)CN, attack of the Yb-H-B bridge bonds results. Decomposition of 2 to the 9-BBN dimer in CD(2)Cl(2) was observed by (11)B and (1)H NMR spectroscopies. Compound 2 was reacted with 2 equiv of the hydride ion abstracting reagent B(C(6)F(5))(3) to afford the solvent-separated ion pair [Yb(THF)(6)][HB(C(6)F(5))(3)](2) (3). Complexes 1, 2, and 3 were characterized by single-crystal X-ray diffraction analysis. Crystal data: 1 is orthorhombic, Pna2(1), a = 21.975(1) A, b = 9.310(1) A, c = 16.816(1) A, Z = 4; 2 is triclinic, P1, a = 9.862(1) A, b = 10.227(1) A, c = 10.476(1) A, alpha = 69.87(1) degrees, beta = 76.63(1) degrees, gamma = 66.12(1) degrees, Z = 1; 3.Et(2)O is triclinic, P1, a = 13.708(1) A, b = 14.946(1) A, c = 17.177(1) A, alpha = 81.01(1) degrees, beta = 88.32(1) degrees, gamma = 88.54(1) degrees, Z = 2.
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Lanthanide−Transition-Metal Carbonyl Complexes: New [Co4(CO)11]2- Clusters and Lanthanide(II) Isocarbonyl Polymeric Arrays. J Am Chem Soc 2003; 126:204-13. [PMID: 14709086 DOI: 10.1021/ja0304852] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two types of Ln(II)-Co(4) isocarbonyl polymeric arrays, [(Et(2)O)(3)(-)(x)()(THF)(x)()Ln[Co(4)(CO)(11)]]( infinity ) (1-3; x = 0, 1) and [(THF)(5)Eu[Co(4)(CO)(11)]]( infinity ) (4), were prepared and structurally characterized. Transmetalation involving Ln(0) and Hg[Co(CO)(4)](2) in Et(2)O yields [(Et(2)O)(3)Ln[Co(4)(CO)(11)]]( infinity ) (1, Ln = Yb; 2, Ln = Eu). Dissolution of the solvent-separated ion pairs [Ln(THF)(x)()][Co(CO)(4)](2) (Ln = Yb, x = 6; Ln = Eu) in Et(2)O affords [(Et(2)O)(2)(THF)Yb[Co(4)(CO)(11)]]( infinity ) (3) and [(THF)(5)Eu[Co(4)(CO)(11)]]( infinity ) (4). In these reactions, oxidation and condensation of the [Co(CO)(4)](-) anions result in formation of the new tetrahedral cluster [Co(4)(CO)(11)](2)(-). The two types of Ln(II)-Co(4) compounds contain different isomers of [Co(4)(CO)(11)](2)(-), and, consequently, the structures of the infinite isocarbonyl networks are distinct. The cluster in [(Et(2)O)(3)(-)(x)()(THF)(x)()Ln[Co(4)(CO)(11)]]( infinity ) (1-3) possesses pseudo C(3)(v)() symmetry (an apical Co, three basal Co atoms; one face-bridging, three edge-bridging, seven terminal carbonyls) and connects to Ln(II) centers through eta(2),micro(4)- and eta(2),micro(3)-carbonyls to generate a 2-D puckered sheet. In contrast, [(THF)(5)Eu[Co(4)(CO)(11)]]( infinity ) (4) incorporates a C(2)(v)() symmetric cluster (two unique Co environments; two face-bridging, one edge-bridging, eight terminal carbonyls), and isocarbonyl linkages (eta(2),micro(4)-carbonyls) to Eu(II) atoms create a 1-D zigzag chain. Complexes 1-4 contain the first reported eta(2),micro(4)-CO bridges between a Ln and a transition-metal carbonyl cluster. Infrared spectroscopic studies revealed that the isocarbonyl associations to Ln(II) persist in solution. The solution structure and dynamic behavior of the [Co(4)(CO)(11)](2)(-) cluster in 1 was investigated by variable-temperature (59)Co and (13)C NMR spectroscopies.
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Abstract
New lanthanide-transition-metal (Ln-M) compounds were prepared and the structural relationships of the metal combinations were discerned. Numerous compounds derived from divalent or trivalent lanthanides and from transition metals in groups 7-11 were isolated. Three different types of interactions were observed: (1). Ln-M direct bonds, (2). ionic associations, and (3). carbonyl or cyanide linkers between the metals. These assorted Ln-M interactions influence the assembly of the compounds, and discrete molecules or polymeric arrays were encountered. The extended arrays spanning one, two, and three dimensions can function as heterogeneous catalyst precursors. Two classes of systems, Ln-M carbonyls and cyanides, are described.
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In honor of Professor Thomas P. Fehlner. Appl Organomet Chem 2003. [DOI: 10.1002/aoc.458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Synthesis of mono- and dihalogenated derivatives of (Me2S)2B12H10 and palladium-catalyzed boron-carbon cross-coupling reactions of the iodides with grignard reagents. Inorg Chem 2003; 42:3199-207. [PMID: 12739960 DOI: 10.1021/ic020600u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two series of compounds, 9-X-1,7-(Me(2)S)(2)B(12)H(9) and 9,10-X(2)-1,7-(Me(2)S)(2)B(12)H(8) (X = Cl, Br, I), have been synthesized from reactions of 1,7-(Me(2)S)(2)B(12)H(10) with various halogenating reagents. In addition, reactions of 1,7-(Me(2)S)(2)B(12)H(10) with 2,4-(NO(2))(2)C(6)H(3)SCl and PhSeBr resulted in 9-(2',4'-(NO(2))(2)C(6)H(3)S)-1,7-(Me(2)S)(2)B(12)H(9) and 9,10-(PhSe)(2)-1,7-(Me(2)S)(2)B(12)H(8), respectively. X-ray studies of the dibromo, monoiodo, and aryl thioether derivatives show that electrophilic substitution in 1,7-(Me(2)S)(2)B(12)H(10) takes place at positions 9 and 10, as in the case of the meta-carborane 1,7-C(2)B(10)H(12). From 1,12-(Me(2)S)(2)B(12)H(10) the halides 2-X-1,12-(Me(2)S)(2)B(12)H(9) (X = Br, I) were prepared. For both 1,7- and 1,12-(Me(2)S)(2)B(12)H(10) the best iodination results were obtained using iodine monochloride in refluxing acetonitrile. In the presence of 5 mol % (PPh(3))(2)PdCl(2) the iodides 9-I-1,7-(Me(2)S)(2)B(12)H(9), 2-I-1,12-(Me(2)S)(2)B(12)H(9), and 9,10-I(2)-1,7-(Me(2)S)(2)B(12)H(8) react with RMgX (R = Me, Ph, Bn; X = Cl, Br) in THF to yield the corresponding B-alkyl- and B-aryl-substituted products in good yields without using CuI as a cocatalyst. The bromo derivative 9-Br-1,7-(Me(2)S)(2)B(12)H(9) did not react under similar conditions. No interference from the nearby Me(2)S substituent was observed in palladium-catalyzed substitution of iodide in 2-I-1,12-(Me(2)S)(2)B(12)H(9). Presumably due to the intramolecular activation of an aryl C-H bond of the benzyl substituent in the intermediate palladium complex, the yield of 9,10-Bn(2)-1,7-(Me(2)S)(2)B(12)H(8) was significantly lower than those of the dimethyl and diphenyl derivatives. The molecular structures of 9-R-1,7-(Me(2)S)(2)B(12)H(9) (R = Ph, Bn) and 2-Bn-1,12-(Me(2)S)(2)B(12)H(9) were obtained by single-crystal X-ray analysis.
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The solid state structure of [b(10)h(11)](-) and its dynamic NMR spectra in solution. Inorg Chem 2003; 42:1175-86. [PMID: 12588155 DOI: 10.1021/ic020540s] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The structure of [PPh(3)(benzyl)][B(10)H(11)] was determined at -123 degrees C and 24 degrees C by single-crystal X-ray analyses. The B(10) core of [B(10)H(11)](-) is similar in shape to that of [B(10)H(10)](2)(-). The 11th H atom asymmetrically caps a polar face of the cluster and shows no tendency for disorder in the solid state. Variable temperature multinuclear NMR studies shed light on the dynamic nature of [B(10)H(11)](-) in solution. In addition to the fluxionality of the cluster H atoms, the boron cage is fluxional at moderate temperatures, in contrast to [B(10)H(10)](2)(-). Multiple exchange processes are believed to take place as a function of temperature. Results of ab initio calculations are presented. Crystal data: [PPh(3)(benzyl)][B(10)H(11)] at -123 degrees C, P2(1)/c, a = 9.988(2) A, b = 18.860(2) A, c = 15.072(2) A, beta = 107.916(8) degrees, V = 2701.5(7) A(3), Z = 4; [PPh(3)(benzyl)][B(10)H(11)] at 24 degrees C, P2(1)/c, a = 10.067(5) A, b = 19.009(9) A, c = 15.247(7) A, beta = 107.952(9) degrees, V = 2775(2) A(3), Z = 4.
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Gas-phase hydrodechlorination of chlorobenzenes over silica-supported palladium and palladium-ytterbium. Appl Organomet Chem 2003. [DOI: 10.1002/aoc.463] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Cyclic Organohydroborate Complexes of Metallocenes. VII. Synthesis, Structure, and Fluxional Behavior of Cp2ZrX{(μ-H)2BC8H14} (X = H, D, Cl). Organometallics 2002. [DOI: 10.1021/om0206249] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Synthesis, structural characterization, and reactions of cyclic organohydroborate half-zirconocene compounds. Inorg Chem 2002; 41:5329-35. [PMID: 12377026 DOI: 10.1021/ic0202817] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cyclic organohydroborate complexes of zirconium monocyclopentadienyl CpZr[(mu-H)(2)BC(5)H(10)](3), 1, and CpZr[(mu-H)(2)BC(8)H(14)](3), 2, were prepared from the reaction of CpZrCl(3) with 3 mol of K[H(2)BC(5)H(10)] and K[H(2)BC(8)H(10)], respectively, in diethyl ether. Compounds 1 and 2 react with the hydride ion abstracting agent B(C(6)F(5))(3) to form the same salt [CpZr(OEt)(OEt(2))(mu-OEt)](2)[HB(C(6)F(5))(3)](2), 5. The complexes CpZr(Cl)[(mu-H)(2)BC(8)H(14)](2), 3, and CpZr(Cl)[(mu-H)(2)BC(8)H(14)](2) [where Cp = C(5)(CH(3))(5)], 4, were prepared from the reaction of CpZrCl(3) and CpZrCl(3) with K[H(2)BC(8)H(10)] in 1:2 molar ratios, respectively. An alpha-hydrogen of a BC(8)H(14) unit forms an agostic interaction with Zr in compound 3 but not in 4. All of the compounds were characterized by single-crystal X-ray diffraction analysis.
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An inclusion complex with [Gd(dmf)(8)](3+) ions encapsulated in pockets of an anionic array of [(Cu(6)(CN)(9))(3-)] infinity units; a cyanide-bridged Cu-Gd layer structure. Angew Chem Int Ed Engl 2002; 41:3609-11, 3515. [PMID: 12370906 DOI: 10.1002/1521-3773(20021004)41:19<3609::aid-anie3609>3.0.co;2-#] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lanthanide-transition-metal carbonyl complexes. 1. Syntheses and structures of ytterbium(II) solvent-separated ion pairs and isocarbonyl polymeric arrays of tetracarbonylcobaltate. Inorg Chem 2002; 41:4936-43. [PMID: 12230398 DOI: 10.1021/ic020254g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transmetalation reactions of metallic ytterbium with Hg[Co(CO)(4)](2) in the coordinating solvents pyridine and THF yield the solvent-separated ion pairs [Yb(L)(6)] [Co(CO)(4)](2) (1a, L = Pyr; 2a, L = THF). The IR spectrum of 1a in pyridine indicates that the tetracarbonylcobaltate anion is not directly bonded to the divalent Yb cation owing to the strong coordinating ability of pyridine. On the other hand, IR spectra of 2a in THF are concentration dependent. In dilute solutions there is an equilibrium between the solvent-separated ion pair and a weak contact ion pair. Higher concentrations of 2a facilitate the formation of a tight ion pair that has a low-frequency isocarbonyl absorption. Remarkably, complexes 1a and 2a are easily transformed in toluene into the two-dimensional sheetlike arrays [(Pyr)(4)Yb[(mu-CO)(2)Co(CO)(2)](2)](infinity) (1b) and [(THF)(2)Yb[(mu-CO)(3)Co(CO)](2).Tol](infinity) (2b). The two-dimensional frameworks are supported by isocarbonyl linkages. Infrared spectra of toluene solutions substantiate the existence of the isocarbonyl bridges with low-frequency absorptions at 1780 cm(-1). Compounds 1b and 2b belong to a rare class of lanthanide-transition-metal carbonyl extended arrays, only three others of which have been structurally established. Dissolving 1b in pyridine regenerates 1a, but the complete conversion of 2b into 2a cannot be achieved. Crystal data: 1a.Pyr is monoclinic, P2(1)/c, a = 11.171(1) A, b = 11.925(1) A, c = 33.978(1) A, beta = 95.10(1) degrees, Z = 4; 2a is monoclinic, C2/c, a = 17.724(1) A, b = 12.468(1) A, c = 18.413(1) A, beta = 100.34(1) degrees, Z = 4; 1b is monoclinic, C2/c, a = 11.047(1) A, b = 13.423(1) A, c = 21.933(1) A, beta = 103.49(1) degrees, Z = 4; 2b is monoclinic, C2/c, a = 28.589(1) A, b = 7.223(1) A, c = 14.983(1) A, beta = 118.90(1) degrees, Z = 4.
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Structure and spectra of 4,5-.mu.-tetracarbonyliron-hexaborane(10), Fe(CO)4B6H10, and its conjugate base, [Fe(CO)4B6H9]-. Organometallics 2002. [DOI: 10.1021/om00030a010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kinetics of carbon-13-labeled carbon monoxide exchange with 12CO in [HM3(CO)11]- and [DM3(CO)11]- (M = ruthenium, osmium): study of the effects of ion pairing and deuterium labeling on the exchange process and hydride activation. Organometallics 2002. [DOI: 10.1021/om00049a014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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