Iron and cobalt nitrosyl 1,2-dithiolenes

Pulsed Electron Paramagnetic Resonance Spectroscopy of33S-Labeled Molybdenum Cofactor in Catalytically Active Bioengineered Sulfite Oxidase

“…Figure S1 depicts the canonical Kohn-Sham (KS) orbitals for the optimized structure of the SO active site model. The overall orbital scheme is typical for a Mo(V) center with d 1 configuration, and spin polarization effects are shown to stabilize the majority spin orbitals such that the singly-occupied molecular orbital (SOMO, 168α) is shifted below the highest occupied orbitals of mainly ligand character. As a result of strong intermixing between metal- and ligand-based orbitals, the d xy -character (in the chosen coordinate system) is spread over orbitals 168α and 169α (~26% Mo character in each orbital, see Table S1).…”

“…All known molybdenum-containing enzymes, with the exception of nitrogenase, contain either one or two pyranopterin dithiolate (molybdopterin; MPT) cofactors (Figure 1) that coordinate to the metal through the two sulfur atoms of the ene-dithiolate (dithiolene) 1 functionality. The pyranopterin dithiolate cofactor is unusual in that both the pyranopterin and the dithiolene portions can have multiple redox forms.…”

“…For sulfite oxidase (SO), hyperfine interactions ( hfi ) and nuclear quadrupole interactions ( nqi ) of magnetic nuclei ( I ≠ 0) near the Mo(V) (d 1 ) center have been measured using high-resolution pulsed electron paramagnetic resonance (EPR) methods and interpreted with the help of the density functional theory (DFT) calculations. These have provided important insights about the active site structure and the reaction mechanism of the enzyme.…”

Σύνθεση Χαρακτηρισμός Και Μελέτη Ιδιοτήτων Συμπλόκων Των Στοιχείων Μεταπτώσεως Με Υποκαταστάτες Που Περιέχουν Άτομα Θείου

“…Γνωρίζοντας τις παραμέτρους γ΄και β οι συντελεστές της πραγματικής (Re χ 3) ) και υποθετικής (Im χ 3) )…”

“…( Η επίδραση της συγκέντρωσης στην πραγματική τρίτης τάξης επιδεκτικότητα χ (3) επίσης μελετήθηκε (σχήμα 4.18). Από το διάγραμμα φαίνεται ότι όσο αυξάνει η συγκέντρωση της ουσίας τόσο αυξάνει και η μη γραμμική αυτή παράμετρος εμφανίζοντας πολύ καλή γραμμική συσχέτιση.…”