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1H NMR T1(min) data and structure in a series of rhenium polyhydride complexes and the contribution of M-H dipole–dipole relaxation by Xiao-Liang Luo; Judith A. K. Howard; Robert H. Crabtree is a Chemistry article available to read on EtoBox.

What is 1H NMR T1(min) data and structure in a series of rhenium polyhydride complexes and the contribution of M-H dipole–dipole relaxation about?

## Abstract The unusual species [ReH~5~(H~2~){P(__p__‐tolyl)~3~}~2~], for which a neutron diffraction study shows an intermediate HH bond distance of 1.357 Å, is studied by variable‐temperature ^1^H NMR spin‐lattice (__T__~1~) relaxation time measurements. The __T__~1~ relaxation rate goes through a maximum at low temperature and the resulting __T__~1~ (min) value is 66 ms. This is within the range of __T__~1~(min) values found for classical ReH~7~L~2~ complexes, so H~2~ complexes with such long HH bond distances are undetectable by the __T__~1~ method. The observed __T__~1~(min) value is compared with that calculated from the neutron diffraction data. We consider not only the usual proton–proton dipole–dipole (HHDD) contributions to the relaxation but also the metal‐hydride dipole–dipole (MHDD) contributions. The latter are shown to be negligible for most transition metals, but not for Nb, V, Re, Mn, Co and Ta. Inclusion of the MHDD contributions leads to better agreement between the calculated and observed __T__~1~(min) values for a series of rhenium polyhydride complexes. The MHDD relaxation also accounts for most of the disparity previously noted between the calculated and ob

Who reads 1H NMR T1(min) data and structure in a series of rhenium polyhydride complexes and the contribution of M-H dipole–dipole relaxation?

Author

Xiao-Liang Luo; Judith A. K. Howard; Robert H. Crabtree

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); John Wiley & Sons Inc.; John Wiley and Sons Ltd; Wiley (ISSN 0749-1581)

Published

1991

Language

EN

Field

Chemistry (Physical Sciences)