Mixed sugar-core-phosphate chelation of D-fructose 1,6-bisphosphate with the (ReO)-O-V(tmen) metal fragment

Sugar phosphates provide metal-binding sites both at their sugar core and at their phosphate group(s). Mixed sugar-core-phosphate chelation has been considered as a typical bonding mode within the physiological pH range for the central metabolite D-fructose 1,6-bisphosphate. The (ReO)-O-V(tmen) metal fragment was used to enrich this coordination type. The formation of the ReO(tmen)(Fruf2,3H(-2)1,6-P2H2-kappa O-3(2,3,P1))](-) monoanion was determined by NMR spectroscopy and mass spectrometry. The model compound rac-glycerol 1-phosphate yielded similar results in terms of NMR spectroscopy. Crystal-structure analyses of ReO(tmen)(rac-Glyc2,3H(-2)1PH-kappa O-3(2,3,P))]center dot 2H(2)O and ReO(phen)(rac-Glyc2,3H(-2)1PH-kappa O-3(2,3,P))]center dot MeOH confirmed the coordination pattern

Photocrystallography and IR spectroscopy of light-induced linkage NO isomers in [RuBr(NO)(2)(PCyp(3))(2)]BF4

International audienceOne single photo-induced linkage NO isomer (PLI) is detected and characterized in the dinitrosyl pentacoordinated compound [RuBr(NO)(2)(PCyp(3))(2)]BF4 by a combination of photocrystallographic and IR analysis. In the ground state, the molecule adopts a trigonal-bipyramidal structure with the two NO ligands almost linear with angles Ru-N1-O1 = 168.92 (16), Ru-N2-O2 = 166.64 (16)degrees, and exactly equal distances of Ru-N = 1.7838 (17) and O-N = 1.158 (2) angstrom. After light irradiation of 405 nm at T = 10 K, the angle of Ru-N2-O2 changes to 114.2 (6)degrees by rotation of the O atom towards the Br ligand with increased distances of Ru-N2 = 1.992 (6) and N2-O2 = 1.184 (8) angstrom, forming a bent kappa N bonded configuration. Using IR spectroscopy, the optimal wavelength and maximum population of 39 (1)% of the PLI is determined. In the ground state (GS), the two symmetric nu(s)(NO) and asymmetric nu(as)(NO) vibrations are measured at 1820 and 1778 cm(-1), respectively. Upon photo-irradiation, the detection of only one new vibrational nu(NO) stretching band at 1655 cm(-1), assigned to the antisymmetric coupled vibration mode and shifted to lower wavenumbers by -123 cm(-1), supports the photocrystallographic result. These experimental results are supported by additional DFT calculations, which reproduce the structural parameters and vibrational properties of both the ground state and the photo-induced linkage isomer well. Especially the experimentally characterized molecular structure of the PLI state corresponds to an energy minimum in the calculations; the stabilization of the bent kappa N bonded configuration of the PLI state originates from specific intramolecular orbital overlap