Solid-state (55)Mn NMR spectroscopy of bis(?-oxo)dimanganese(IV) [Mn(2)O(2)(salpn)(2)], a model for the oxygen evolving complex in photosystem II.
 

Solid-state (55)Mn NMR spectroscopy of bis(?-oxo)dimanganese(IV) [Mn(2)O(2)(salpn)(2)], a model for the oxygen evolving complex in photosystem II.

Solid-state (55)Mn NMR spectroscopy of bis(?-oxo)dimanganese(IV) [Mn(2)O(2)(salpn)(2)], a model for the oxygen evolving complex in photosystem II.

J Am Chem Soc. 2010 Dec 1;132(47):16727-9

Authors: Ellis PD, Sears JA, Yang P, Dupuis M, Boron TT, Pecoraro VL, Stich TA, Britt RD, Lipton AS

We have examined the antiferromagneticly coupled bis(?-oxo)dimanganese(IV) complex [Mn(2)O(2)(salpn)(2)] (1) with (55)Mn solid-state NMR at cryogenic temperatures and first-principle theory. The extracted values of the (55)Mn quadrupole coupling constant, C(Q), and its asymmetry parameter, ?(Q), for 1 are 24.7 MHz and 0.43, respectively. Further, there was a large anisotropic contribution to the shielding of each Mn(4+), i.e. a ?? of 3375 ppm. Utilizing broken symmetry density functional theory, the predicted values of the electric field gradient (EFG) or equivalently the C(Q) and ?(Q) at ZORA, PBE QZ4P all electron level of theory are 23.4 MHz and 0.68, respectively, in good agreement with experimental observations.

PMID: 21058720 [PubMed - indexed for MEDLINE]



Source: PubMed