Reduction of a 1,4-diazabutadiene and 2,2’-bipyridine using magnesium(I) compounds

Abstractβ-diketiminate coordinated magnesium(I) compounds, [{(ArNacnac)Mg}2] (ArNacnac = [(ArNCMe)2CH]– (Ar = 2,6-diisopropylphenyl (Dip) or mesityl (Mes)), have been utilized as reducing agents in reactions with the redox active 1,4-diazabutadiene, (ButNCH)2 (ButDAB), and 2,2’-bipyrine (bipy). These reactions led to one-electron reductions of the unsaturated substrate, and formation of the highly colored radical complexes, [(ArNacnac) Mg(ButDAB•)] and [(MesNacnac)Mg(bipy•)(bipy)]. The X-ray crystal structures of the compounds reveal each to possess one singly reduced ButDAB or bipy ligand.

Influence of the Nucleophilic Ligand on the Reactivity of Carbonyl Rhenium(I) Complexes towards Methyl Propiolate: A Computational Chemistry Perspective

A comparative theoretical study on the reactivity of the complexes [ReY(CO)3(bipy)] (Y = NH2, NHMe, NHpTol, OH, OMe, OPh, PH2, PHMe, PMe2, PHPh, PPh2, PMePh, SH, SMe, SPh; bipy = 2,2′-bipyridine) towards methyl propiolate was carried out to analyze the influence of both the heteroatom (N, O, P, S) and the alkyl and/or aryl substituents of the Y ligand on the nature of the product obtained. The methyl substituent tends to accelerate the reactions. However, an aromatic ring bonded to N and O makes the reaction more difficult, whereas its linkage to P and S favour it. On the whole, ligands with O and S heteroatoms seem to disfavour these processes more than ligands with N and P heteroatoms, respectively. Phosphido and thiolato ligands tend to yield a coupling product with the bipy ligand, which is not the general case for hydroxo, alcoxo or amido ligands. When the Y ligand has an O/N and an H atom the most likely product is the one containing a coupling with the carbonyl ligand, which is not always obtained when Y contains P/S. Only for OMe and OPh, the product resulting from formal insertion into the Re-Y bond is the preferred.

catena-Poly[[[bis(glycolato-κ2 O,O′)copper(II)]-μ-4,4′-bipyridine-κ2 N:N′] ethane-1,2-diol monosolvate]

In the title compound, {[Cu(C2H3O3)2(C10H8N2)]·C2H6O2} n , the CuII cation is six-coordinated in a slightly distorted octahedral manner by two N atoms from two different bridging 4,4′-bipyridine (4,4′-bipy) ligands and four O atoms from two individual glycolate anions. The 4,4′-bipy ligand bridges adjacent CuII centres, generating linear chains running parallel to the [1\overline10] direction. In the crystal structure, adjacent chains are further connected by classical O—H...O hydrogen bonds, resulting in a two-dimensional supermolecular network structure parallel to (100). The C atom of one of the ethane-1,2-diol solvent molecules is disordered over two sets of sites with occupancies of 0.51 (2) and 0.49 (2).

Crystallization and structural properties of a family of isotopological 3D-networks: the case of a 4,4′-bipy ligand–M2+ triflate system

Desolvation process characterization of a flexible coordination network performed by time-resolved single-crystal X-ray diffraction. Influence of the metal centre on the network stability.

Poly[[(μ4-benzene-1,3,5-tricarboxylato-κ4O1:O1′:O2:O3)bis(2,2-bipyridine-κ2N,N′)(μ2-hydroxido)dicopper(II)] trihydrate]

In the title two-dimensional coordination polymer, {[Cu2(C9H3O6)(OH)(C10H8N2)2]·3H2O}n, each of the two independent CuIIatoms is coordinated by a bridging OH group, two O atoms from two benzene-1,3,5-tricarboxylate (L) ligands and two N atoms from a 2,2- bipyridine (bipy) ligand in a distorted square-pyramidal geometry. EachLligand coordinates four CuIIatoms, thus forming a polymeric layer parallel to thebcplane with bipy molecules protruding up and down. The lattice water molecules involved in O—H...· O hydrogen bonding are situated in the inner part of each layer. The crystal packing is consolidated by π–π interactions between the aromatic rings of bipy ligands from neigbouring layers [intercentroid distance = 3.762 (3) Å].

(2,2′-Bipyridine-κ2N,N′)bis(4-formylbenzoato-κO1)copper(II)

The title mononuclear CuIIcomplex, [Cu(C8H5O3)2(C10H8N2)], is comprised of a CuIIcation, two 4-formylbenzoate (L−) ligands and a 2,2′-bipyridine (bipy) ligand. The CuIIion and bipy ligand lie on a crystallographic twofold rotation axis; the CuIIion is coordinated by two N atoms from one bipy ligand and two O atoms from two different carboxylate groups of twoL−ligands, exhibiting effectively a distorted square-planar geometry. The complex molecules are interlinked to generate two-dimensional supramolecular layers in theabplane, formed by C—H...O hydrogen bonds, where the O acceptor is the O atom from the carboxylate group not involved in coordination to the CuIIion. The two-dimensional layers are stacked in a sequenceviaC—H...O hydrogen-bonding interactions where the formyl O atom acts as acceptor.

Redetermination of (2,2′-bipyridine-κ2N,N′)dichloridopalladium(II) dichloromethane solvate

In the title compound, [PdCl2(C10H8N2)]·CH2Cl2, the Pd2+ion is four-coordinated in a slightly distorted square-planar environment by two N atoms of the 2,2′-bipyridine (bipy) ligand and two chloride ions. The compound displays intramolecular C—H...Cl hydrogen bonds and pairs of complex molecules are connected by intermolecular C—H...Cl hydrogen bonds. Intermolecular π–π interactions are present between the pyridine rings of the ligand, the shortest centroid–centroid distance being 4.096 (3) Å. As a result of the electronic nature of the chelate ring, it is possible to create π–π interactions to its symmetry-related counterpart [3.720 (2) Å] and also with a pyridine ring [3.570 (3) Å] of the bipy unit. The present structure is a redetermination of a previous structure [Vicenteet al.(1997). Private communication (refcode PYCXMN02). CCDC, Cambridge, England]. In the new structure refinement all H atoms were located in a difference Fourier synthesis. Their coordinates were refined freely, together with isotropic displacement parameters.

Poly[[[(2,2′-bipyridine-κ2 N,N′)cobalt(II)]-μ3-5-hydroxyisophthalato-κ4 O,O′:O′′:O′′′] dihydrate]

In the title compound, {[Co(C8H4O5)(C10H8N2)]·2H2O]} n or {[Co(OH-BDC)(2,2′-bipy)]·2H2O]} n (where OH-H2BDC is 5-hydroxyisophthalic acid and 2,2′-bipy is 2,2′-bipyridine), the Co atoms are chelated by two N atoms from the 2,2′-bipy ligand and by four O atoms from OH-BDC ligands in a highly distorted octahedral geometry. OH-BDC acts as a tetradentate ligand, with one carboxylate group chelating one Co atom and the other binding in a monodentate fashion to two other Co atoms to form a one-dimensional zigzag chain. In the crystal structure, one of the solvent water molecules lies on a crystallographic twofold axis. The one-dimensional molecular chains are assembled into a two-dimensional network via O—H...O hydrogen-bonding interactions, while π–π stacking interactions generate a three-dimensional open framework between the two-dimensional networks.