Hydrogen-Bonded Networks Based on Cobalt(II), Nickel(II), and Zinc(II) Complexes of N,N'-Diethylurea

N,N'-diethylurea (DEU) was employed as a ligand to form the octahedral complexes [M(DEU)6]2+ (M=Co, Ni and Zn). Compounds [Co(DEU)6](BF4)2 (1), [Co(DEU)6](CIO4)2 (2), [Ni(DEU)6](CIO4)2 (3), and [Zn(DMU)6](CIO4)2 (4) have been prepared from the reactions of DEU and the appropriate hydrated metal(II) salts in EtOH in the presence of 2,2-dimethoxypropane. Crystal structure determinations demonstrate the existence of [M(DEU)6]2+ cations and CIO4− (in 2–4) or BF4− (in 1) counterions. The [M(DEU)6]2+ cations in the solid state are stabilized by a pseudochelate effect due to the existence of six strong intracationic N-H ⋯ O(DEU) hydrogen bonds. The [M(DEU)6]2+ cations and counterions self-assemble to form hydrogen-bonded 2D architectures in 2–4 that conform to the kgd (kagome dual) network, and a 3D hydrogen-bonded rtl (rutile) network in 1. The nature of the resulting supramolecular structures is influenced by the nature of the counter-ion. The complexes were also characterized by vibrational spectroscopy (IR)

A Synthetic Approach of New Trans-Substituted Hydroxylporphyrins

The synthesis of new trans A2B2-substituted porphyrins bearing oxygenic substituent (methoxy, acetoxy, hydroxy) at the periphery of the ring are described. All of the synthesized products were characterized by 1H-N.M.R., 13C-N.M.R., and H.R.M.S. Electrochemical studies revealed two one-electron oxidations and two reductions. In addition, the X-ray structure of one methoxy-derivative was determined

Mononuclear and Dinuclear Manganese(II) Complexes from the Use of Methyl(2-pyridyl)ketone Oxime

The reactions of methyl(2-pyridyl)ketone oxime, (py)C(Me)NOH, with manganese(II) sulfate monohydrate have been investigated. The reaction between equimolar quantities of MnSO4 · H2O and (py)C(Me)NOH in H2O lead to the dinuclear complex [Mn2(SO4)2{(py)C(Me)NOH}4] · (py)C(Me)NOH, 1 · (py)C(Me)NOH, while employment of NaOMe as base affords the compound [Mn(HCO2)2{(py)C(Me)NOH}2] (2). The structures of both compounds have been determined by single crystal X-ray diffraction. In both complexes, the organic ligand chelates through its nitrogen atoms. The IR data are discussed in terms of the nature of bonding and the structures of the two complexes

Bis(2-hydroxy­imino­methyl-6-methoxy­phenolato-κ2 O 1,N)cobalt(II)

In the title compound, [Co(C8H8NO3)2], the CoII atom lies on a centre of inversion and is coordinated in a slightly distorted square-planar geometry by two N and two O atoms from the 2-hydroxy­imino­methyl-6-methoxy­phenolate ligands. Intra­molecular O—H⋯O hydrogen bonds are formed and the complexes form stacks along the b axis, with an inter­planar separation of 3.332 (1) Å between complexes. Pairs of C—H⋯O contacts are formed between complexes in neighbouring stacks

A Mononuclear and a Mixed-Valence Chain Polymer Arising from Copper(II) Halide Chemistry and the Use of 2,2′-Pyridil

Reactions of 2,2′-pyridil (pyCOCOpy) with CuCl2 · 2H2O and CuBr2 in EtOH yielded the mononuclear complex [Cu(pyCOOEt)2Cl2] · H2O (1) and the one-dimensional, mixed-valence complex [Cu2ICuII(pyCOOEt)2Br4]n (2), respectively. Both complexes crystallize in the triclinic space group P 1¯. The lattice constants are a = 8.382(2), b = 9.778(2), c = 7.814(2), α = 101.17(1), β = 114.55(1), γ = 94.14(1)° for 1 and a = 8.738(1), b = 9.375(2), c = 7.966(1), α = 79.09(1), β = 64.25(1), γ = 81.78(1)° for 2. 2,2′-pyridil undergoes a metal-assisted alcoholysis and oxidation leading to decomposition and yielding the ethyl picolinate (pyCOOEt) ligand. The autoredox process associated with the reduction of copper(II) to copper(I) in the case of complex 2 is discussed in terms of the increased redox activity of the copper(II) bromide system relative to the copper(II) chloride system

Unfair commercial practices in e-commerce

Τα τελευταία χρόνια, λόγω της κυριαρχίας και ανόδου του ηλεκτρονικού εμπορίου και της τεχνητής νοημοσύνης έχουν παρατηρηθεί πρακτικές διαφήμισης και μάρκετινγκ σε διαδικτυακές πλατφόρμες και μέσα κοινωνικής δικτύωσης που παραβιάζουν την Οδηγία για τις αθέμιτες εμπορικές πρακτικές και απειλούν την ευημερία και την προστασία των καταναλωτών. Μια μεγάλη ποικιλία τεχνικών διαδικτυακού μάρκετινγκ, συμπεριλαμβανομένης της εξατομικευμένης διαφήμισης, των παγίδων συνδρομής, της εγγενούς διαφήμισης, influencer marketing, των διαφημιστικών παιχνιδιών και των κριτικών καταναλωτών έχει αποδειχθεί ιδιαιτέρως προβληματική. Σκοπός της διατριβής μου ήταν ο εντοπισμός τέτοιων αθέμιτων εμπορικών πρακτικών στο ευρύ πεδίο του ηλεκτρονικού εμπορίου και η κριτική της τυχόν αποτελεσματικότητας ή μη του υπάρχοντος νομικού πλαισίου.There have been increased concerns during the past years, due to the rise of e-Commerce and Artificial Intelligence, about advertising and marketing practices in online platforms and social media that infringe the Unfair Commercial Practices Directive and threaten the consumers’ welfare and protection. A great variety of online marketing techniques, including personalised advertising, subscription traps, bait and drip pricing, native advertising, influencer marketing, advertorials, fishing, advergames and consumer reviews, was found to be particularly problematic. The scope of my dissertation was to detect such unfair commercial practices within the broad field of e-commerce and elaborate on the efficiencies and inefficiencies of the existing legal framework

Synthesis, X-Ray Structure, and Characterization of Catena-bis(benzoate)bis{N,N-bis(2-hydroxyethyl)glycinate}cadmium(II)

The reaction of N, N-bis(2-hydroxyethyl)glycine (bicine; bicH3) with Cd(O2CPh)2 · 2H2O in MeOH yielded the polymeric compound [Cd2(O2CPh)2(bicH2)2]n(1). The complex crystallizes in the tetragonal space group P41212. The lattice constants are a = b = 12.737(5) and c = 18.288(7) Å. The compound contains chains of repeating {Cd2(O2CPh)2(bicH2)2} units. One CdII atom is coordinated by two carboxylate oxygen, four hydroxyl oxygen, and two nitrogen atoms from two symmetry-related 2.21111 (Harris notation) bicH2− ligands. The other CdII atom is coordinated by six carboxylate oxygen atoms, four from two bicH2− ligands and two from the monodentate benzoate groups. Each bicinate(-1) ligand chelates the 8-coordinate, square antiprismatic CdII atom through one carboxylate oxygen, the nitrogen, and both hydroxyl oxygen atoms and bridges the second, six-coordinate trigonal prismatic CdII center through its carboxylate oxygen atoms. Compound 1 is the first structurally characterized cadmium(II) complex containing any anionic form of bicine as ligand. IR data of 1 are discussed in terms of the coordination modes of the ligands and the known structure

In Search for Titanocene Complexes with Improved Cytotoxic Activity: Synthesis, X-Ray Structure, and Spectroscopic Study of Bis(η5-cyclopentadienyl)difluorotitanium(IV)

The 1 : 2 reaction of [Ti(η5-C5H5)2Cl2] and AgF in CHCl3/H2O yielded the fluoro analog [Ti(η5-C5H5)2F2] (1) in almost quantitative yield (C5H5 is the cyclopentadienyl group). The coordination about the TiIV atom formed by two fluoro ligands and the centroids of the cyclopentadienyl rings is distorted tetrahedral. The compound crystallizes in the orthorhombic space group C2cm. The lattice constants are a = 5.9055(4), b = 10.3021(5), c = 14.2619(9) Å, and α = β = γ = 90°. The complex has been characterized by elemental analyses and spectroscopic (IR, 1H NMR) data. A structural comparison of the four members of the [Ti(η5-C5H5)2X2] family of complexes (X = F, Cl, Br, I) is attempted

Use of the 2-Pyridinealdoxime/N,N′-Donor Ligand Combination in Cobalt(III) Chemistry: Synthesis and Characterization of Two Cationic Mononuclear Cobalt(III) Complexes

The use of 2-pyridinealdoxime (paoH)/N,N′-donor ligand (L-L) “blend” in cobalt chemistry has afforded two cationic mononuclear cobalt(III) complexes of the general type [Co(pao)2(L-L)]+, where L-L = 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy). The CoCl2/paoH/L-L (1 : 2 : 1) reaction system in MeOH gives complexes [CoIII(pao)2(phen)]Cl·2H2O (1·2H2O) and [CoIII(pao)2(bpy)]Cl·1.5MeOH (2·1.5MeOH). The structures of the complexes were determined by single-crystal X-ray crystallography. The CoIII ions are six-coordinate, surrounded by three bidentate chelating ligands, that is, two pao− and one phen or bpy. The deprotonated oxygen atom of the pao− ligand remains uncoordinated and participates in hydrogen bonding with the solvate molecules. IR data of the complexes are discussed in terms of the nature of bonding and the known structures