Browsing by Author "DuChane, Christine M."

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    Crystal structures of (eta(4)-cycloocta-1,5-diene)bis-(1,3-dimethylimidazol-2-ylidene)iridium(I) iodide and (eta(4)-cycloocta-1,5-diene)bis(1,3-diethyl-imidazol-2-ylidene)iridium(I) iodide
    Bernier, Chad M.; DuChane, Christine M.; Merola, Joseph S. (2020-05)
    The title complexes, (eta(4) -cycloocta-1,5-diene)bis(1,3-dimethylimidazol-2-yl-idene)iridium(I) iodide, [Ir(C5H8N2)(2)(C8H12)]I, (1) and (eta(4)-cycloocta-1,5-diene)bis(1,3-diethylimidazol-2-ylidene)iridium(I) iodide, [Ir(C7H12N2)(2)(C8H12)]I, (2), were prepared using a modified literature method. After carrying out the oxidative addition of the amino acid l-proline to [Ir(COD)(IMe)(2)]I in water and slowly cooling the reaction to room temperature, a suitable crystal of 1 was obtained and analyzed by single-crystal X-ray diffraction at 100 K. Although this crystal structure has previously been reported in the Pbam space group, it was highly disordered and precise atomic coordinates were not calculated. A single crystal of 2 was also obtained by heating the complex in water and letting it slowly cool to room temperature. Complex 1 was found to crystallize in the monoclinic space group C2/m, while 2 crystallizes in the orthorhombic space group Pccn, both with Z = 4.
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    Hexafluoroacetylacetonate (hfac) as ligand for pentamethylcyclopentadienyl (Cp*) rhodium and iridium complexes: Some surprising results, including an Ir3Na1O4 cubane structure
    DuChane, Christine M.; Merola, Joseph S. (2020-12-14)
    Attempts to prepare hexafluoroacetylacetonate (hfac) piano stool complexes of pentamethylcyclopentadienyl Cp∗ iridium and rhodium led to a surprising array of unexpected products. The desired complex, Cp∗M(hfac)Cl, was obtained following the reaction of sodium hexafluoroacetylacetonate (hfacNa) with [Cp ∗MCl 2 ] 2 in dichloromethane. Variations of this synthetic method resulted in twelve unique crystal- lographically identified products, eleven of which contain the hfac ligand or a trifluoroacetylacetonate (TFA) ligand, either coordinated to the metal or as a non-coordinating anion. Five dinuclear Cp ∗iridium hydroxo-bridged products with various fluorinated non-coordinating anions were obtained. The most in- triguing two complexes are trinuclear Cp ∗Ir III hydroxo-bridged clusters that have, at their core, an Ir 3 NaO 4 cubane structure. Attempts to devise rational syntheses of the hydroxo-bridged cluster compounds were not successful. Generation of the TFA moieties likely occurred following degradation of Cp ∗Ir(hfac)Cl. The reaction between [Cp ∗MCl 2 ] 2 and 1,1,1-trifluoroacetylacetonate (tfac) proceeded as expected to give Cp ∗M(tfac)Cl with no observed side product formation, indicating that the metal-coordinated tfac moiety is significantly more stable than the metal-coordinated hfac moiety.
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    mer-Trichloridotris(tetrahydrothiophene-κS)-iridium(III): preparation and comparison with other mer trichloridotris(tetrahydrothiophene-κS)metal complexes
    Brown, Loren C.; DuChane, Christine M.; Merola, Joseph S. (International Union of Crystallography, 2016-08-09)
    The title complex, [IrCl₃(C₄H₈S)₃], was prepared according to a literature method. A suitable crystal was obtained by diffusion of pentane into a di­chloro­methane solution and analyzed by single-crystal X-ray diffraction at 100 K. The title complex is isotypic with mer-tri­chlorido­tris­(tetra­hydro­thio­phene-κS)rhodium(III). However, the orientation of the tetra­hydro­thio­phene rings is different from an earlier report of mer-tri­chlorido­tris­(tetra­hydro­thio­phene-κS)iridium(III) deposited in the Cambridge Structural Database. The IrS₃Cl₃ core shows a nearly octa­hedral structure with various bond angles within 1-2° of the perfect 90 or 180° expected for an octa­hedron. The structure of the title compound is compared with the previous iridium complex as well as the rhodium and other octa­hedral metal tris-tetra­hydro­thio­phene compounds previously structurally characterized. DFT calculations were performed, which indicate the mer isomer is significantly lower in energy than the fac isomer by 50.1 kJ mol⁻¹, thereby accounting for all compounds in the CSD being of the mer geometry. Powder X-ray diffraction of the bulk material showed that the preparation method yielded only the isomorph reported in this communication.
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    Noble Metal Organometallic Complexes Display Antiviral Activity against SARS-CoV-2
    Chuong, Christina; DuChane, Christine M.; Webb, Emily M.; Rai, Pallavi; Marano, Jeffrey M.; Bernier, Chad M.; Merola, Joseph S.; Weger-Lucarelli, James (MDPI, 2021-05-25)
    SARS-CoV-2 emerged in 2019 as a devastating viral pathogen with no available preventative or treatment to control what led to the current global pandemic. The continued spread of the virus and increasing death toll necessitate the development of effective antiviral treatments to combat this virus. To this end, we evaluated a new class of organometallic complexes as potential antivirals. Our findings demonstrate that two pentamethylcyclopentadienyl (Cp*) rhodium piano stool complexes, Cp*Rh(1,3-dicyclohexylimidazol-2-ylidene)Cl2 (complex 2) and Cp*Rh(dipivaloylmethanato)Cl (complex 4), have direct virucidal activity against SARS-CoV-2. Subsequent in vitro testing suggests that complex 4 is the more stable and effective complex and demonstrates that both 2 and 4 have low toxicity in Vero E6 and Calu-3 cells. The results presented here highlight the potential application of organometallic complexes as antivirals and support further investigation into their activity.