Jeffrey J. Ellison

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGadolinium(III) Chelates as MRI Contrast Agents: Structure, Dynamics, and ApplicationsPeter Caravan, Jeffrey J. Ellison, Thomas J. McMurry, and Randall B. LaufferView Author Information EPIX Medical, Inc., 71 Rogers Street, Cambridge, Massachusetts 02142 Cite this: Chem. Rev. 1999, 99, 9, 2293–2352Publication Date (Web):August 20, 1999Publication History Received22 February 1999Revised24 June 1999Published online20 August 1999Published inissue 8 September 1999https://pubs.acs.org/doi/10.1021/cr980440xhttps://doi.org/10.1021/cr980440xresearch-articleACS PublicationsCopyright © 1999 American Chemical SocietyRequest reuse permissionsArticle Views27447Altmetric-Citations3831LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Coordination compounds,Ions,Ligands,Molecular structure,Molecules Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIsolation and structural characterization of unsolvated lithium arylsKarin Ruhlandt-Senge, Jeffrey J. Ellison, Rudolf J. Wehmschulte, Frank Pauer, and Philip P. PowerCite this: J. Am. Chem. Soc. 1993, 115, 24, 11353–11357Publication Date (Print):December 1, 1993Publication History Published online1 May 2002Published inissue 1 December 1993https://pubs.acs.org/doi/10.1021/ja00077a038https://doi.org/10.1021/ja00077a038research-articleACS PublicationsRequest reuse permissionsArticle Views2590Altmetric-Citations180LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (4)»Supporting Information Supporting Information Get e-Alerts

The amphiphilic gadolinium complex MS-325 ((trisodium-{(2-(R)-[(4,4-diphenylcyclohexyl) phosphonooxymethyl] diethylenetriaminepentaacetato) (aquo)gadolinium(III)}) is a contrast agent for magnetic resonance angiography (MRA). MS-325 consists of two slowly interconverting diastereoisomers, A and B (65:35 ratio), which can be isolated at pH > 8.5 (TyeklAr, Z.; Dunham, S. U.; Midelfort, K.; Scott, D. M.; Sajiki, H.; Ong, K.; Lauffer, R. B.; Caravan, P.; McMurry, T. J. Inorg. Chem. 2007, 46, 6621-6631). MS-325 binds to human serum albumin (HSA) in plasma resulting in an extended plasma half-life, retention of the agent within the blood compartment, and an increased relaxation rate of water protons in plasma. Under physiological conditions (37 degrees C, pH 7.4, phosphate buffered saline (PBS), 4.5% HSA, 0.05 mM complex), there is no statistical difference in HSA affinity or relaxivity between the two isomers (A 88.6 +/- 0.6% bound, r1 = 42.0 +/- 1.0 mM(-1) s(-1) at 20 MHz; B 90.2 +/- 0.6% bound, r1 = 38.3 +/- 1.0 mM(-1) s(-1) at 20 MHz; errors represent 1 standard deviation). At lower temperatures, isomer A has a higher relaxivity than isomer B. The water exchange rates in the absence of HSA at 298 K, kA298 = 5.9 +/- 2.8 x 10(6) s(-1), kB298 = 3.2 +/- 1.8 x 10(6) s(-1), and heats of activation, DeltaHA = 56 +/- 8 kJ/mol, DeltaHB = 59 +/- 11 kJ/mol, were determined by variable-temperature 17O NMR at 7.05 T. Proton nuclear magnetic relaxation dispersion (NMRD) profiles were recorded over the frequency range of 0.01-50 MHz at 5, 15, 25, and 35 degrees C in a 4.5% HSA in PBS solution for each isomer (0.1 mM). Differences in the relaxivity in HSA between the two isomers could be attributed to the differing water exchange rates.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSterically Encumbered Iron(II) Thiolate Complexes: Synthesis and Structure of Trigonal Planar [Fe(SR)3]- (R = 2,4,6-t-Bu3C6H2) and Moessbauer Spectra of Two- and Three-Coordinate ComplexesFrederick M. MacDonnell, Karin Ruhlandt-Senge, Jeffrey J. Ellison, R. H. Holm, and Philip P. PowerCite this: Inorg. Chem. 1995, 34, 7, 1815–1822Publication Date (Print):March 1, 1995Publication History Published online1 May 2002Published inissue 1 March 1995https://pubs.acs.org/doi/10.1021/ic00111a032https://doi.org/10.1021/ic00111a032research-articleACS PublicationsRequest reuse permissionsArticle Views910Altmetric-Citations114LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (2)»Supporting Information Supporting Information Get e-Alerts

Coordination number two, ten valence electrons, and highly bent ligands owing to the weak secondary interactions with ortho mesityl substituents—these characteristic features are present in one (shown on the right) of the first two thiolato complexes with a two-coordinate FeII center. Low coordinate iron centers of this kind bound to sulfur are of particular interest in light of the crystal structure of the FeMo cofactor of nitrogenase.