The evolution of a craft: Post-Byzantine bookbinding between the late fifteenth and the early eighteenth century from the libraries of the Iviron Monastery in Mount Athos/Greece and the St. Catherine's monastery in Sinai/Egypt.

The thesis investigates the ways through which the Greek-style bookbinding was gradually supplanted by European bookbinding, a process which occurred between the late fifteenth century, after the fall of the Byzantine Empire, and the early eighteenth century. The Greek-style bookbinding is a distinctive typological binding structure confined in the milieu of the Byzantine and post-Byzantine civilization. The research is based on two major monastic libraries, those of the Iviron monastery in Mount Athos/Greece and of the St. Catherine's monastery in Sinai/Egypt. The primary material of the research consists of a detailed survey of 419 bookbindings dated between the late fifteenth and the early eighteenth century. To collect and store the collected data a survey methodology had to be devised and a computer database appositely built. Through the analysis of the collected data twelve major bookbinding ateliers are identified and described in full detail, representing both monastic communities, providing the most extensive body of information on bindings of the Greek-Orthodox Christian monastic communities so far. It is through the description of these ateliers that the various influences, both from the West and the East, under which the aforementioned evolution occurred, are identified, considered, and interpreted. A statistical analysis is provided at the end of the thesis using tables and graphics in the effort to illustrate the major changes in time and space of the most significant bookbinding features, both technical and decorative. Except providing a full photographic survey of the bookbindings described in the examination of twelve different bookbinding ateliers, graphic representations of many technical and decorative features, and a complete indexed list of all the 593 decorative motifs recorded, the thesis also tries to explore, whenever possible, how these bookbindings reflect the social, religious and commercial life of the time. Since there is only little, isolated and dispersed, information published, and practically no systematic research on this specific subject and for the specific period considered here, the thesis aims to contribute in filling in a gap as well as providing a methodology for further research in the subject

Bis[5-(pyridin-2-yl)pyrazine-2-carbo­nitrile-κ2 N 4,N 5]silver hexa­fluorido­phosphate

In the mononuclear title complex, [Ag(C10H6N4)2]PF6, two κ2 N,N′-chelating 5-(pyridin-2-yl)pyrazine-2-carbonitrile ligands surround the AgI atom, forming a distorted N4 tetra­hedral coordination geometry. The mononuclear units are inter­connected through π–π inter­actions [centroid–centroid distances = 3.801 (2) and 3.979 (3) Å] and the hexa­fluoridophosphate anions are embedded within the inter­stices. C N⋯π inter­actions [N⋯centroid = 3.519 (2) Å] and C—H.⋯N hydrogen-bonding inter­actions also occur

catena-Poly[[copper(II)-bis­[μ-bis­(pyridin-3-yl)methanone-κ2 N:N′]] bis­(tetra­fluorido­borate)]

In the title complex, {[Cu(C11H8N2O)2](BF4)2}n, the CuII ion is situated on an inversion centre and adopts an N4F2 octa­hedral coordination geometry with four N atoms from four different bis­(pyridin-3-yl)methanone ligands at the equatorial sites and two independent tetra­fluoridoborate anions weakly bonded at the axial sites via two F atoms [Cu⋯F = 2.613 (3) Å]. Chains with the bridging ligands are formed along the a axis. C—H⋯F inter­actions stabilize the structure. C—O⋯π inter­actions also occur

Poly[[(μ2-di-3-pyridyl­methanone-κ2 N:N′)(μ2-hexa­fluoro­silicato-κ2 F:F′)copper(II)] dihydrate]

In the title complex, {[Cu(SiF6)(C11H8N2O)2]·2H2O}n, the CuII atom adopts an N4F2-octa­hedral coordination geometry with four pyridine N atoms in the equatorial sites and two F atoms in the axial sites. The di-3-pyridyl­methanone and hexa­fluoro­silicate ligands act as bidentate ligands, linking symmetry-related CuII atoms. Water mol­ecules form O—H⋯O and O—H⋯F hydrogen bonds with the di-3-pyridyl­methanone and hexa­fluoro­silicate ligands. The Cu2+ and SiF6 2− ions are each located on a twofold axis

Matrix effects on the magnetic properties of a molecular spin triangle embedded in a polymeric film

Molecular triangles with competing Heisenberg interactions and significant Dzyaloshinskii–Moriya interactions (DMI) exhibit high environmental sensitivity, making them potential candidates for active elements for quantum sensing. Additionally, these triangles exhibit magnetoelectric coupling, allowing their properties to be controlled using electric fields. However, the manipulation and deposition of such complexes pose significant challenges. This work explores a solution by embedding iron-based molecular triangles in a polymer matrix, a strategy that offers various deposition methods. We investigate how the host matrix alters the magnetic properties of the molecular triangle, with specific focus on the magnetic anisotropy, aiming to advance its practical applications as quantum sensors

A tetragonal core with asymmetric iron environments supported solely by bis(μ-OH){μ-(O-H···O)} bridging and terminal pyridine amide (N, O) coordination: a new member of the tetrairon(III) family

Room-temperature aerobic reaction of [Fe(MeCN)4][ClO4]2 with 1,3-bis(2-pyridinecarboxamido)propane (H2bpp) yields the tetrairon(III) complex [Fe4(H2bpp)4(μ-OH)2(μ-OHO)][ClO4]7·2H2O·xMeCN (1·xMeCN, 0≤x≤3). Crystal structure determination reveals that 1·3MeCN is a new member of the tetrairon(III) family, bridged solely by two hydroxido ligands and a localized {O-H···O}3- bridging unit. The properties of the "tetragonal" core [Fe4(μ-OH)2{μ-(O-H···O)}]7+ have been investigated by variable-temperature magnetic and Mossbauer spectroscopic measurements. Successful modeling of the data has revealed asymmetric iron environments and three types of magnetic exchange interactions [through μ-OH and μ-O/μ-OH of μ-(O-H···O) bridges]. This tetragonal core is a valuable addition to the tetrairon(III) cluster family from inorganic and bioinorganic perspectives

First Demonstration of Magnetoelectric Coupling in a Polynuclear Molecular Nanomagnet: Single-Crystal EPR studies of [Fe3O(O2CPh)6(py)3](ClO4)*py under static electric fields

Single-crystal EPR experiments show that the highly symmetric antiferromagnetic half-integer spin triangle [Fe3O(O2CPh)6(py)3](ClO4)·py (1) possesses a ST = 1/2 ground state exhibiting high g-anisotropy due to antisymmetric exchange (Dzyaloshinskii-Moriya) interactions. EPR experiments under static electric fields parallel to the triangle’s plane (i.e. perpendicular to the magnetic z-axis) reveal that this ground state couples to externally applied electric fields. This magnetoelectric coupling causes an increase in the intensity of the intradoublet EPR transition and does not affect its resonance position when B0||z. The results are discussed on the basis of theoretical models correlating the spin chirality of the ground state with the magnetoelectric effect

Polyanisotropic Magnetoelectric Coupling in an Electrically Controlled Molecular Spin Qubit

International audienceTwo molecular spin qubits are studied with pulsed Electron Paramagnetic Resonance (EPR) spectroscopy under electric fields to assess their magnetoelectric (ME) couplings and electric spin control. [Fe 3 O(PhCOO) 6 (py) 3 ]ClO 4 ⋅py (Fe 3) is characterized by strong Dzyaloshinskii-Moriya interactions (DMI) which induce important magnetoanisotropy, whereas the DMI in [Cr 3 O(PhCOO) 6 (py) 3 ]ClO 4 ⋅0.5py (Cr 3) is 1-2 orders of magnitude weaker. Fe 3 is observed to demonstrate a clear ME effect whose intensity shows an unprecedented dependence on the molecular orientation within the electric field E (electroanisotropy) and on the relative orientations of the molecular z-axis, the Zeeman field B 0 and E (magnetoelectric anisotropy). The electric control in Fe 3 is shown to be coherent and the ME effect exhibits complex dynamics characterized by saturation and oscillatory effects. On the other hand, Cr 3 exhibits no discernible ME effect, which correlates well with its negligible DMI

Synthesis and characterization of the tetranuclear iron(III) complex of a new asymmetric multidentate ligand. A structural model for purple acid phosphatases

The ligand, 2-((2-hydroxy-5-methyl-3-((pyridin-2-ylmethylamino)methyl)benzyl)(2-hydroxybenzyl)amino)acetic acid (H(3)HPBA), which contains a donor atom set that mimics that of the active site of purple acid phosphatase is described. Reaction of H(3)HPBA with iron(III) or iron(II) salts results in formation of the tetranuclear complex, [Fe-4(HPBA)(2)(OAc)(2)(mu-O)(mu-OH)(OH2)(2)]ClO4 center dot 5H(2)O. X-Ray structural analysis reveals the cation consists of four iron(III) ions, two HPBA(3-) ligands, two bridging acetate ligands, a bridging oxide ion and a bridging hydroxide ion. Each binucleating HPBA(3-) ligand coordinates two structurally distinct hexacoordinate iron(III) ions. The two metal ions coordinated to a HPBA(3-) ligand are linked to the two iron(III) metal ions of a second, similar binuclear unit by intramolecular oxide and hydroxide bridging moieties to form a tetramer. The complex has been further characterised by elemental analysis, mass spectrometry, UV-vis and MCD spectroscopy, X- ray crystallography, magnetic susceptibility measurements and variable-temperature Mossbauer spectroscopy