Wednesday, September 27, 2006

Prog NMR: Silver NMR review article - Glenn Penner

Progress in Nuclear Magnetic Resonance Spectroscopy
Volume 49, Issue 2 , 30 September 2006, Pages 151-167

Silver NMR spectroscopy

Glenn H. Penner and Xiaolong Liu

Department of Chemistry, University of Guelph, Guelph, Ont., Canada N1G 2W1

Keywords: NMR spectroscopy; Solid state NMR; Silver

Friday, September 01, 2006

JMR: Bodenhausen, indirect detection of 14N via 1H (HMQC type experiment)

Journal of Magnetic Resonance
Vol: 182 Issue: 1, September, 2006

Indirect detection of nitrogen-14 in solids via protons by nuclear magnetic resonance spectroscopy

Simone Cavadini a, Sasa Antonijevic a, , Email Address, Adonis Lupulescu a, Geoffrey Bodenhausen a, b
a Laboratoire de Résonance Magnétique Biomoléculaire, Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne, Batochime, CH-1015 Lausanne, Switzerland
b Département de Chimie, associé au CNRS, Ecole Normale Supérieure, 24 rue Lhomond 75231, Paris Cedex 05, France

This Communication describes the indirect detection of 14 N nuclei (spin I = 1) in solids by nuclear magnetic resonance (NMR) spectroscopy. The two-dimensional correlation method used here is closely related to the heteronuclear multiple quantum correlation (HMQC) experiment introduced in 1979 to study molecules in liquids, which has recently been used to study solids spinning at the magic angle. The difference is that the coherence transfer from neighboring 1 H nuclei to 14 N is achieved via a combination of J couplings and residual dipolar splittings (RDS). Projections of the two-dimensional correlation spectra onto the 14 N dimension yield powder patterns which reflect the 14 N quadrupolar interaction. In contrast to the indirect detection of 14 N via 13 C nuclei that was recently demonstrated [Gan, J. Am. Chem. Soc. 128 (2006) 6040; Cavadini et. al., J. Am. Chem. Soc., 128 (2006) 7706], this approach may benefit from enhanced sensitivity, and does not require isotopic enrichment in 13 C, although the 1 H line-widths may have to be reduced upon selective deuteration.

Organometallics: SSNMR of ferrocene derivatives

Organometallics, ASAP Article 10.1021/om060468w S0276-7333(06)00468-7
Web Release Date: August 18, 2006

A Solid-Gas Route to Polymorph Conversion in Crystalline [FeII(5-C5H4COOH)2]. A Diffraction and Solid-State NMR Study

Dario Braga, Fabrizia Grepioni,* and Marco Polito*
Dipartimento di Chimica G Ciamician, Università di Bologna, 40126 Bologna, Italy
Michele R. Chierotti, Silvano Ellena, and Roberto Gobetto*
Dipartimento di Chimica IFM, Università di Torino, 101256 Torino, Italy


Crystalline form I (monoclinic) and form II (triclinic) of ferrocene dicarboxylic acid [Fe(5-C5H4COOH)2] have been employed in solid-gas reactions at room temperature with the gaseous bases NH3, NH2(CH3), and NH(CH3)2. The two crystal forms behave in exactly the same way in the solid-gas reaction, generating the same products, identified as the anhydrous crystalline salts [NH4]2[Fe(5-C5H4COO)2] (1), [NH3CH3]2[Fe(5-C5H4COO)2] (2), and [NH2(CH3)2]2[Fe(5-C5H4COO)2] (3). Interestingly though, all these crystals revert via vapor release exclusively to the metastable crystalline form I. Starting materials and products have been investigated by single-crystal and powder diffraction and by 13C, 15N CPMAS and 1H MAS methods.

JACS: Fyfe & Brouwer: Structures of Zeolite Host-Guest Systems by NMR

J. Am. Chem. Soc., ASAP Article 10.1021/ja060744y S0002-7863(06)00744-X
Web Release Date: August 17, 2006

Optimization, Standardization, and Testing of a New NMR Method for the Determination of Zeolite Host-Organic Guest Crystal Structures

Colin A. Fyfe* and Darren H. Brouwer

Contribution from the Department of Chemistry, University of British Columbia, R300, 6174 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z3


An optimized and automated protocol for determining the location of guest sorbate molecules in highly siliceous zeolites from 29Si INADEQUATE and 1H/29Si cross polarization (CP) magic-angle spinning (MAS) NMR experiments is described. With the peaks in the 29Si MAS NMR spectrum assigned to the unique Si sites in the zeolite framework by a 2D 29Si INADEQUATE experiment, the location of the sorbate molecule is found by systematically searching for sorbate locations for which the measured rates of 1H/29Si cross polarization of the different Si sites correlate linearly with 1H/29Si second moments calculated from H-Si distances. Due to the 1H/29Si cross polarization being in the "slow CP regime" for many zeolite-sorbate complexes, it is proposed that the CP rate constants are best measured by 1H/29Si cross polarization drain experiments, if possible, to avoid complications that may arise from fast 1H and 29Si T1 relaxations. An algorithm for determining the sorbate molecule location is described in detail. A number of ways to effectively summarize and display the large number of solutions which typically result from a prediction of the structure from the CP MAS NMR data are presented, including estimates of the errors involved in the structure determinations. As a working example throughout this paper, the structure of the low loaded p-dichlorobenzene/ZSM-5 complex is determined under different conditions from solid-state 1H/29Si CP MAS NMR data, and the solutions are shown to be in excellent agreement with the known single-crystal X-ray diffraction structure. This structure determination approach is shown to be quite insensitive to the use of relative rate constants rather than absolute values, to the detailed structure of the zeolite framework, and relatively insensitive to temperature and motions.

Prog. in NMR: platinum anti-cancer drugs and 195Pt NMR - Review article

Review article
Progress in Nuclear Magnetic Resonance Spectroscopy
Volume 49, Issue 1 , 15 August 2006, Pages 65-98

Insights into the mechanism of action of platinum anticancer drugs from multinuclear NMR spectroscopy

Susan J. Berners-Price, Luca Ronconi and Peter J. Sadler

School of Biomedical, Biomolecular and Chemical Sciences, University of Western Australia, Crawley, Perth, WA 6009, Australia
School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK

Keywords: NMR; Platinum drugs; 195Pt NMR; 15N NMR; [1H,15N] NMR; Proteins; Glutathione; DNA; Aquation; Kinetics

Prog. in NMR: Paramagnetic relaxitivity -Review article

Review article
Progress in Nuclear Magnetic Resonance Spectroscopy

Volume 49, Issue 1 , 15 August 2006, Pages 45-64

Relaxivity in paramagnetic systems: Theory and mechanisms

Lothar Helm

Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-BCH, CH-1015 Lausanne, Switzerland

Keywords: Paramagnetic NMR relaxation; EPR relaxation; Zero-field splitting; MRI contrast agents