Publications by authors named "Mark F Roll"
Article Synopsis
- Research is focused on finding new biologically active compounds, specifically Azothioformamides (ATFs), which can form stable coordination complexes with metals like copper for potential anticancer and antimicrobial therapies.
- In this study, different ATF ligands with varying heterocyclic groups were synthesized and complexed with Cu(I) salts, which were chosen for their potential lower toxicity and effective binding properties.
- The results indicated that smaller pyrrolidine-substituted ATFs showed stronger binding to Cu(I) salts and had varying levels of antimicrobial activity, particularly against some cancer cell lines, while the ATF ligands alone showed limited effectiveness.
The synthesis and crystal structure of bis-[3,3-diethyl-1-(phenyl-imino-κ)thio-urea-κ]silver hexa-fluorido-phosphate.
Acta Crystallogr E Crystallogr Commun
September 2019
The structure of the title complex, [Ag(CHNS)]PF, has monoclinic (2/) symmetry, and the silver atom has a distorted square-planar geometry. The coordination complex crystallized from mixing silver hexa-fluorido-phosphate with a concentrated tetra-hydro-furan solution of ,-di-ethyl-phenyl-azo-thio-formamide [ATF; systematic name: 3,3-diethyl-1-(phenyl-imino)-thio-urea] under ambient conditions. The resultant coordination complex exhibits a 2:1 ligand-to-metal ratio, with the silver(I) atom having a fourfold AgNS coordination sphere, with a single PF counter-ion.
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- Redox-active ligands like arylazothioformamide (ATF) complicate the determination of oxidation states for both the ligands and metal centers due to their three distinct oxidation states.
- ATF's interaction with metals leads to significant color changes, making it useful for detecting and separating metals.
- The study utilizes X-ray crystallography and computational modeling to clarify the oxidation states in ATF-metal complexes, finding that complexes from zerovalent metals contain dicationic metal centers with singly reduced ATF, while using Cu(I) maintains both the metal's oxidation state and the ligand's neutral form.
The cubic symmetry of octafunctional octaphenylsilsesquioxanes [ROPS, (RC6H4SiO(1.5))8] coupled with a 1 nm diameter offers exceptional potential to assemble materials in three dimensions with perfect control of periodicity and the potential to tailor global properties at nanometer length scales. OPS itself is very inert and insoluble and can only be functionalized via electrophilic reactions with difficulty and with poor substitutional selectivity.
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