Ultrahigh-field NMR spectroscopy of quadrupolar transition metals: Mn-55 NMR of several solid manganese carbonyls

Kristopher J. Ooms, Kirk W. Feindel, Victor V. Terskikh, Roderick E. Wasylishen

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

Mn-55 NMR spectra acquired at 21.14 T (nu(L)(Mn-55) = 223.1 MHz) are presented and demonstrate the advantages of using ultrahigh magnetic fields for characterizing the chemical shift tensors of several manganese carbonyls: eta(5)-CpMn(CO)(3), Mn-2(CO)(10), and (CO)(5)MnMPh3 (M = Ge, Sn, Pb). For the compounds investigated, the anisotropies of the manganese chemical shift tensors are less than 250 ppm except for eta(5)-CpMn(CO)(3), which has an anisotropy of 920 ppm. At 21.14 T, one can excite the entire m(I) = 1/2 m(I) = -1/2 central transition of eta(5)-CpMn(CO)(3), which has a breadth of approximately 700 kHz. The breadth arises from second-order quadrupolar broadening due to the 55Mn quadrupolar coupling constant of 64.3 MHz, as well as the anisotropic shielding. Subtle variations in the electric field gradient tensors at the manganese are observed for crystallographically unique sites in two of the solid pentacarbonyls, resulting in measurably different C-Q values. MQMAS experiments are able to distinguish four magnetically unique Mn sites in (CO)(5)MnPbPh3, each with slightly different values of delta(iso), C-Q, and eta(Q).

Original languageEnglish
Pages (from-to)8492-8499
Number of pages8
JournalInorganic Chemistry
Volume45
Issue number21
DOIs
Publication statusPublished - 16 Oct 2006
Externally publishedYes

Cite this