Nuclear Magnetic Resonance Spectroscopy

BY B.E. MANN

1 Introduction

Following the criteria established in earlier volumes, only books and reviews directly relevant to this chapter are included and the reader who requires a complete list is referred to the Specialist Periodical Reports 'Nuclear Magnetic Resonance', where a complete list of books and reviews is given. Reviews which are of direct relevance to a section of this report are included in the beginning of that section rather than here. Papers where only 1, 2H, 13C, 19F and/or 31P NMR spectroscopy is used are only included when they make a non-routine contribution, but complete coverage of relevant papers is still attempted where nuclei other than these are involved. In view of the greater restrictions on space and the ever growing number of publications, many more papers in marginal areas have been omitted. This is especially the case in the sections on solid-state NMR spectroscopy, silicon and phosphorus.

A number of reviews have also been published: 'NMR in metals, metal particles and metal clusters' which contains 55Mn, 63Cu, 65Cu, 105Pd, 107Ag, 109Ag, 111Cd, 113Cd, 195Pt and 197Au NMR data, Tris(pyrazolyl)methane ligands: the neutral analogues of tris(pyrazolyl)borate ligands', which contains 113Cd NMR data, 'NMR spectroscopy of quadrupole nuclei in supercritical fluids', and 'Enantioselective homogeneous catalysis: transferring chirality via phosphine complexes. A 2D NMR approach'.

A number of papers have been published which are too broadly based to fit into a later section and are included here. Indirect spin–spin coupling tensors have been calculated for diatomic molecules such as LiH, KNa and HC1 and compared with experiment. The influence of metal cation complexation on six different esters of ethylene glycol has been studied using 1H, 7Li, 11B, 13C, 17O, 13P and 87Rb NMR spectroscopy. Radiofrequency-mediated dipolar recou-pling among half-integer quadrupolar spins has been investigated for 23Na2. The binding of Mg2+, Mn2+ and [Co(NH3) 6]3+ to hairpin ribozyme domains has been determined by NMR spectroscopy. Density functional calculations of shielding have been applied to 13C, 17O, 51V, 53Cr, 55Mn, 57Fe, 59Co and 61Ni chemical shifts in [VOC13], [VF5], [Cr(CO)6], [CrO4]2-, [Mn(CO)6]+, [MnO4]-, [Fe(CO)5], [(η 5-C5H5)Fe], [FeO4], [Co(CN)6]3-, [Co(NH3)]3+ and [Ni(CO)4]. Relativistic effects for NMR shielding constants have been calculated for 53Cr, 55Mn, 57Fe, 95Mo, 99Tc, 99Ru, 183W, 187Re and 189Os in [MO4]n- and [M(CO)6], M = Cr, Mo, W. The symmetry of metal complexes has been studied using 13C isotope shifts. Pulse field gradient spin-echo measurements have been used to determine molecular diffusion in organo-metallic chemistry. 1H, 11B, 13C and 17O NMR spectroscopy has been used to study the complexation of CoCl2, NiCl2 and CuCl2 salts with three tris(oxaalkyl) borates. One-bond nuclear spin–spin coupling constants involving 183W, 195Pt, 199Hg and207Pb have been calculated using relativistic corrections. The coupling constants and anisotropies of XF, X = C1, Br, I and T1X, X = F, Cl, Br, I, have been calculated and the paper contains 35C1, 37C1, 79Br, 81Br, 127I, 203Tl and 205Tl data. The shielding polarizabilities of H2O2, F2, HC=CH, H2CO, NH3, HCN and HNC have been calculated.

2 Stereochemistry

This section is subdivided into eleven parts which contain NMR information about Groups 1 and 2 and transition-metal complexes presented by Groups according to the Periodic Table. Within each Group, classification is by ligand type.

2.1 Complexes of Groups 1 and 2. – Two reviews, entitled 'Applications of 7Li NMR in biomedicine' and 'In vivo imaging of the pharmacodynamics and pharmacokinetics of lithium', have appeared.

Diffusion-ordered NMR spectroscopy (DOSY) of THF solvated n-butyl-lithium aggregates has been reported and 1H and 7Li NMR spectroscopy has been used to identify a dimer and a tetramer. 1H-66Li HOESY has been used to investigate ion pairing in compounds such as [(Me3SiCH2)2CuLi]. 1J(13C(13C) and J(13 C(1H) have been determined in 2-lithiothiophene, 2-lithio-N-methylpyrrole and 2-lithiofuran. The 6Li chemical shift in (1) is at δ - 5.07 and has been attributed to the ring current. The solution structures of {(amino)phenylsilyl}lithiums have been investigated by 7Li, 13C, 15N and 29Si NMR spectroscopy and J(29Si7Li) and J(29Si15N) observed. NMR data have also been reported for [Li(THF)2(μ-H)AlH(SiMe3) (μ-H)AlH(SiMe3)H], (6Li, 27A1, 29Si), [(pmdta)LiCH2SPh], (6Li), [Ph2Si(CH2M)CH2N(CH2 -CH2OMe) 2], (M = Li, SnBu3; 6Li, 29Si, 199Sn), (2), (6Li, 15N), [Me-N(CH2)4C HLi], (6Li, 15N), Et α-lithioisobutyrate, (6Li), [(R1O)R22 Si-CHLiSiMe3], (6Li), (3), (11B), [Li(THF)2{Al[C(SiMe3)3] (SMe)3}], (7Li, 27Al, 29Si), [LiC(SiMe2CH2PPh2)3], (7Li, 29Si), (4), (7Li, 29Si), [Me2MC-(MXMe2)(SiMe3)2CLi (SiMe3)2], (M = Si, Ge, Sn; 29Si), [Li(2-C6H4PPh2-NSiMe3)] 2, [Sn(2-C6H4PPh2 -NSiMe3)2], (7Li, 29Si, 119Sn), [PhC=CLiBF3], (6Li, 11B), [H2C=CMeCH2NEtC9 H6Li], (15N), [{Li(tmen)}2 {3-(η3-C3H3SiR13-1)2SiR22], (7Li), (5), (7Li, 29Si), (6), (7Li, 29Si), [(Me3Si)3 Si-(Me2Si)2 (Me3Si)2SiLi], (29Si), (7), (7Li, 29Si), [(THF)Li3{Si(NPri)3 (NHPri)}] 2, (7Li, 29Si), and [ButSi(OSiMe2NPh)3GeLi(THF)3], (7Li, 29Si).

Li-1H HOESY has been used to characterize two chiral amides prepared from (R)-(Me2NCH2CH2) (l-Ph-2-pyrrolidin-l-yl-ethyl)amine and (R)-(MeOCH2 CH2)(-l-Ph-2-pyrrolidin-l-yl-ethyl)amine. Diffusion of [LiN-(O2SCF3)2] in a PVDF-type gel polymer has been investigated using NMR spectroscopy. NMR data have also been reported for [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII].

The solvation of Li+ in LiPF6 dissolved in propylene carbonate solutions has been studied using the NMR field gradient technique. Self diffusion of lithium electrolytes in propylene carbonate, and copolymers of maleic anhydride and tetraethylene glycol divinyl ether has been investigated. 6Li, 7Li and 31P NMR spectroscopy has been used to study Li+/Mg2+ competition for red blood cell membrane phospholipids. NMR data have also been reported for α-lithioisobutyrate, (6Li), [LiOCHPh2], (7Li), [Li{Al-(OCH2Ph) 4}], (27A1), and [Li2, {(R)-binol}] (7Li).

The optical ac Stark effect in 23Na NMR spectra has been studied. The electric quadrupole moments of 26Na, 27Na, 28Na and 29Na have been measured by (β-NMR spectroscopy in single crystals of NaNO3. Relative ionophoric activities have been probed using 23Na NMR spectroscopy. Intra- and extra-cellular Na+ have been quantified using 23Na NMR spectroscopy. 1H, 13C and 23Na NMR spectroscopy has been used to study sodium polyacrylate...