Journal article
Investigation of the Coordination Interactions of S-(Pyridin-2-ylmethyl)-l-Cysteine Ligands with M(CO)3+ (M = Re, 99mTc)
Inorganic chemistry, Vol.48(22), pp.10625-10634
11/16/2009
DOI: 10.1021/ic901159r
Abstract
Development of new ligands for feo-M(OH2)3(CO) 3+ (M = Re, 99mTc) led the investigation with S-(pyridin-2-ylmethyl)L-cysteine, 1. The ligand 1 has potential to coordinate with the metal through three different tridentate modes: tripodal through cysteine (O,N,S) and two linear involving the S-pyridyl and cysteine (O,S,N Py, N,S,NPy). From the reaction with 1, two species were observed in the 1H NMR, where the primary product was the linear feo-Re(N,S, Npy-1 XCO)3-, 2a, complex. To identify the coordination mode of the minor product, functionalized analogues of 1 were prepared from S-(pyridin-2-ylmethyl)-Boc-L-cysteine-methyl ester, 3, with orthogonal protecting groups on the C terminus (methyl ester) in S-(pyridin-2-ylmethyl)-L-cysteine methyl ester, 4, or N terminus (Boc) in S-(pyridin2-ylmethyl)-Boc-L-cysteine, 6, that specifically directed the coordination mode of IaO-M(H2O)3(CO)3+ to either N1S, Npy or O,S,NPy, respectively. Two diastereomers [feo-Re(CO) 3(N,S,NPy-4)]+, 5a and 5b, were observed and independently characterized by X-ray structure analysis and NMR in high yield with 4. Surprisingly, the O,S,NPy Re complex with ligand 6 was not observed and simplified versions, 3-(pyridin-2-ylmethylthio) propanoic acid, 7, and 2-(pyridin-2-ylmethylthio)acetic acid, 8, were investigated. Ligand 7 did not yield the desired linear tridentate O,S,NPy product. However, the shorter ligand 8 formed fec-Re(CO)3(O,S,NPy-8), 9, in high yield. 99mTc labeling studies were conducted and yielded similar results to the rhenium complex and effective (>99%) at 10-5 M ligand concentration. © 2009 American Chemical Society.
Details
- Title: Subtitle
- Investigation of the Coordination Interactions of S-(Pyridin-2-ylmethyl)-l-Cysteine Ligands with M(CO)3+ (M = Re, 99mTc)
- Creators
- Haiyang He - Department of Chemistry, Washington State University, P.O. Box 644630, Pullman, Washington 99164Jennifer E Morley - Department of Chemistry, Washington State University, P.O. Box 644630, Pullman, Washington 99164Brendan Twamley - University Research Office, University of Idaho, Moscow, Idaho 8384Ryan H Groeneman - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242-1294Dejan-Krešimir Buč̌ar - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242-1294Leonard R MacGillivray - Department of Chemistry, University of Iowa, Iowa City, Iowa 52242-1294Paul D Benny - Department of Chemistry, Washington State University, P.O. Box 644630, Pullman, Washington 99164
- Resource Type
- Journal article
- Publication Details
- Inorganic chemistry, Vol.48(22), pp.10625-10634
- DOI
- 10.1021/ic901159r
- ISSN
- 0020-1669
- eISSN
- 1520-510X
- Language
- English
- Date published
- 11/16/2009
- Academic Unit
- Chemistry; Pharmaceutical Sciences and Experimental Therapeutics
- Record Identifier
- 9984217454502771
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