Methyl 2-(4-hy­droxy-1-methyl-2-oxo-1,2-dihydro­quinolin-3-yl)acetate

In the title compound, C13H13NO4, the bicyclic quinolone fragment and the ester group are approximately orthogonal, making a dihedral angle of 83.3 (2)° and an intramolecular C—H⋯O interaction occurs. In the crystal, inter­molecular O—H⋯O hydrogen bonding generates a zigzag chain along the c axis

Hexa­kis­(dimethyl­formamide-κO)manganese(II) (dimethyl­formamide-κO)pentakis(­thio­cyanato­-κN)chromate(III)

The title compound, [Mn(C3H7NO)6][Cr(NCS)5(C3H7NO)], was obtained unintentionally as a product of an attempted synthesis of heterometallic complexes based on Reineckes anion using manganese powder, Reineckes salt and 1-(2-hy­droxy­eth­yl)tetra­zole as starting materials. The crystal structure of the complex consists of an [Mn(dmf)6]2+ cation and a [Cr(NCS)5(dmf)]2− anion (dmf = dimethyl­formamide). The MnII and CrIII atoms show a slightly distorted octa­hedral MnO6 and CrN5O coordination geometries with adjacent angles in the range 85.29 (13)–95.96 (14)°

Ethyl 2-(4-hydr­oxy-1-methyl-2-oxo-1,2-dihydro­quinolin-3-yl)acetate

In the title compound, C14H15NO4, the bicyclic fragment and the ester group form a dihedral angle of 86.7 (2)°. Inter­molecular O—H⋯O and C—H⋯O hydrogen bonding connects mol­ecules into a helix along the crystallographic b axis

Diammine(2,2′-bipyridine)­bis(thio­cyan­ato­-κN)cobalt(III) diamminetetra­kis(thio­cyanato­-κN)chromate(III) aceto­nitrile disolvate

The new heterometallic title complex, [Co(NCS)2(C10H8N2)(NH3)2][Cr(NCS)4(NH3)2]·2CH3CN, has been prepared using the open-air reaction of cobalt powder, Reineckes salt and 2,2′-bipyridine (dpy) in acetonitrile. The crystal structure consists of discrete cationic [Co(NCS)2(NH3)2(dpy)]+ and anionic [Cr(NCS)4(NH3)2]− building blocks, both with 2 symmetry, and acetonitrile solvent mol­ecules, which are linked together by N—H⋯N hydrogen bonds, forming extended supra­molecular chains. Furthermore, N—H⋯S, C—H⋯S and C—H⋯N hydrogen bonds inter­link neighbouring chains into a three-dimensional framework. The Co atom is in an elongated octa­hedral coordination environment with two N atoms from the dpy ligands and two NCS-groups in the equatorial plane and with two NH3 mol­ecules at the axial positions. The CrIII ion is octa­hedraly coordinated by two NH3 mol­ecules at the axial positions and four NCS-groups in the equatorial plane. Intensity statistics indicated non-merohedral twinning with the twin matrix [100; 00; 0]. The refined ratio of the twin components is 0.530 (1):0.470 (1)

Aromaticity in heterocyclic analogues of benzene : comprehensive analysis of structural aspects, electron delocalization and magnetic characteristics

The degree of aromaticity of six-membered monoheterocycles with IV-VI group heteroatoms (C(6)H(5)X, where X = SiH, GeH, N, P, As, O(+), S(+), Se(+)) was analyzed using the results of ab initio calculations at the MP2/cc-pvtz level. Values of common aromaticity indices including those based on electronic delocalization properties, structural-dynamic features and magnetic properties all indicate high aromaticity of all considered heterocycles. A decrease in aromaticity is observed with increasing atomic number of the heteroatom, except in the case of the pyrylium cation. However, not all types of indices or even different indices within the same type correlate well among each other. Ring currents have been obtained at the HF/cc-pvdz level using the ipsocentric formulation. Ring current maps indicate that in the case of cationic heterocycles the ring current persists in all molecules under consideration. The different conclusions reached depending on the type of index used are a manifestation of the fact that when not dealing with hydrocarbons, aromaticity is ill-defined. One should always express explicitly which property of the molecules is considered to establish a degree of "aromaticity"

Tris(2,2′-bipyridine-κ2 N,N′)cobalt(III) tris­(oxalato-κ2 O 1,O 2)ferrate(III) mono­hydrate

The title compound, [Co(C10H8N2)3][Fe(C2O4)3]·H2O, con­sists of two discrete tris­(chelate) metal ions (CoIIIN6 and FeIIIO6 chromophores) and a water mol­ecule. The structure is highly symmetrical; the CoIII and FeIII ions occupy positions with site symmetry 3.2. The coordination polyhedra of the metal atoms have a nearly octa­hedral geometry with noticeable trigonal distortions. The Co—N and Fe—O bond lengths are equal by symmetry, viz. 1.981 (2) and 1.998 (4) Å, respectively. The cations and anions are arranged alternately along their threefold rotation axes parallel to [001], forming chains that are packed in a hexa­gonal manner. The water mol­ecules occupy voids between the chains. The crystal under investigation was an inversion twin

2-Hydroxy­imino-N′-[1-(2-pyrid­yl)ethyl­idene]propanohydrazide

The title compound, C10H12N4O2, features an intra­molecular N—H⋯N hydrogen bond formed between the imine NH and oxime N atoms. The oxime group and the amide C=O bond are anti to each other. In the crystal, mol­ecules are connected by O—H⋯O hydrogen bonds into supra­molecular zigzag chains along the c axis

14-(2,3-Dichloro­phen­yl)-9,10-dimethyl­benzimidazo[1,2-a]benzo[f][1,8]naphthyridine-6-carbonitrile

In the title compound, C27H16Cl2N4, the benzimidazo[1,2-a]benzo[f][1,8]naphthyridine system is nearly planar (r.m.s. deviation for all non-H atoms = 0.033 Å). The dichloro­phenyl substituent is rotated by −67.5 (2)° from this plane. In the crystal structure, mol­ecules form stacks along the crystallographic (100) direction due to π–π stacking inter­actions with a centroid–centroid distance of 3.4283 (9) Å

The synthesis of Benzoazines on the base of o-Bromomethylbenzophenone derivatives

Convenient and efficient methods for the preparation of novel phthalazine and pyrazino[1,2-b]isoquinoline derivatives are reported that utilized the reaction of [2-(bromomethyl)phenyl](4-chlorophenyl)methanone with 1,2-dinucleophiles. The crystal structure for 11-(4-Chlorophenyl)-1-oxo-1,2-dihydropyrazino[1,2-b]isoquinolin-5-ium bromide is also described

Ethyl 5-[(1H-benzoimidazol-2-yl)amino­carbon­yl]-4-hydr­oxy-2-methyl-6-oxo-1-propyl-1,6-dihydro­pyridine-3-carboxyl­ate–ethanol–methanol (4/2/1)

The asymmetric unit of the title compound, 4C20H22N4O5·2C2H6O·CH4O, contains two pyridine-3-carboxyl­ate mol­ecules, one ethanol mol­ecule and one methanol mol­ecule disordered about in a centre of symmetry. The pyridinone ring, the carbamide group and the bicyclic fragment in both independent mol­ecules are planar within 0.03 Å due to the formation of intra­molecular O—H⋯O and N—H⋯O hydrogen bonds. The formation of these latter inter­actions also causes the redistribution of the electron density within the hydroxy­pyridone fragment, with the result that some bonds are elongated compared with values in the literature and some others are shorter. In the crystal phase, the pyridine-3-carboxyl­ate mol­ecules form layers parallel to (010), which are inter­linked through hydrogen bonds mediated by the bridging solvate mol­ecules. A terminal ethyl group in one of the mol­ecules is disordered over two sites of equally occupancy