The “Historical Materials BAG”: A New Facilitated Access to Synchrotron X-ray Diffraction Analyses for Cultural Heritage Materials at the European Synchrotron Radiation Facility

The European Synchrotron Radiation Facility (ESRF) has recently commissioned the new Extremely Brilliant Source (EBS). The gain in brightness as well as the continuous development of beamline instruments boosts the beamline performances, in particular in terms of accelerated data acquisition. This has motivated the development of new access modes as an alternative to standard proposals for access to beamtime, in particular via the “block allocation group” (BAG) mode. Here, we present the recently implemented “historical materials BAG”: a community proposal giving to 10 European institutes the opportunity for guaranteed beamtime at two X-ray powder diffraction (XRPD) beamlines—ID13, for 2D high lateral resolution XRPD mapping, and ID22 for high angular resolution XRPD bulk analyses—with a particular focus on applications to cultural heritage. The capabilities offered by these instruments, the specific hardware and software developments to facilitate and speed-up data acquisition and data processing are detailed, and the first results from this new access are illustrated with recent applications to pigments, paintings, ceramics and wood

Transition metal complexes with thiosemicarbazide-based ligands. Part 45. Synthesis, crystal and molecular structure of [2,6-diacetylpyridine bis(S-methylisothiosemicarbazonato)]diazide-iron(III)

The template reaction of a warm methanolic solution of FeCl3.6H2O, S-methylisothiosemicarbazidehydroiodide and 2,6-diacetylpyridine in the presence of LiOAc and NaN3 yielded the high-spin complex [Fe(HL)(N3)2], were HL is the monoanion of the ligand 2,6-diacetylpyridine bis(S-methylisothiosemicarbazone). X-Ray analysis of the complex showed its pentagonal-bipyramidal configuration, with pentadenate (N5) HL in the equatorial plane and two monodentate azide groups in the axial positions. Crystal data are: monoclinic, P21/c, a = 1.0263(2), b = 1.2525(2), c = 1.6660(3) nm, b = 98.94°, V = 2.1154 nm3, Z = 4, rx = 1.499 g cm-3, r0 = 1.48 g cm-3, F(000) = 984, m = 9.40 cm-3