As part of an anti­psychotic drug discovery program, we report the crystal structure of the title compound, C₂₄H₂₃ClN₄O. The mol­ecule has a tricyclic framework with a characteristic buckled V-shaped pyridobenzoxazepine unit, with the central seven-membered heterocycle in a boat configuration. The piperazine ring displays a chair conformation with the 2-phenyl-ethyl substituent assuming an equatorial orientation. There are two crystallographically independent, but virtually identical, mol­ecules in the asymmetric unit.

The crystal structure of the title compound, 2C₃₀H₂₄Cl₂N₆·C₅H₁₂·C₃H₆O, shows the presence of two geometric forms of the C₃₀H₂₄Cl₂N₆ mol­ecule, each exhibiting the characteristic buckled nature of the dibenzodiazepine nucleus with the central seven-membered heterocycle in a boat conformation. Form A contains a twofold rotation axis and form B a centre of symmetry. The solvent molecules are disordered equally over two sites.

The title compound, C₁₀H₇Cl₃O, obtained as a major byproduct from a classical Schmidt reaction. The cyclohexyl ring is distorted from a classical chair conformation, as observed for monocyclic analogues, presumably due to conjugation of the planar annulated benzo ring and the ketone group (r.m.s. deviation 0.024 Å). There are no significant intermolecular interactions.

The title mol­ecule, C₂₀H₃₁NO₈, has pseudo-C2 symmetry about the C-N bond, with the bis­(tert-butoxy­carbon­yl)amino group twisted from the benzene ring plane by ca 60° and the bulky tert-butoxy­carbonyl (Boc) groups are orientated away from the substituted aniline group. As part of an anti­bacterial drug discovery programme furnishing analogues of platensimycin, we unexpectedly synthesized the bis-Boc-protected aniline.

The centrosymmetric title compound, C₂₈H₂₀Cl₂N₆O₂, features a tricyclic framework with the characteristic V-shape of the pyridobenzoxazepine nucleus and with the central seven-membered heterocycle having a classical boat conformation. The piperazine ring displays an almost-perfect chair conformation, with the tricyclic nuclei assuming a pseudo-equatorial orientation.

The title compound, C₁₇H₁₅BrN₄O₃S, was formed by base-assisted N-alkyl­ation of (1,1-dioxo-2-phenyl-2,3-dihydro-1H-1λ⁶,2,3,5-thia­triazol-4-yl)dimethyl­amine with p-bromo­phen­acyl bromide, followed by ring expansion and aerial oxidation to form an unusual 5-acyl-substituted 3-amino-1,1-dioxo-1,2,4,6-thia­triazine. The thiatriazine ring adopts an envelope conformation, with the S atom displaced by 0.308 (2) Å from the plane of the other five atoms.

The title compound, also known as sodium nicotinate, Na⁺·C₆H₄NO₂^-, consists of two unique Na atoms coordinated to two unique pyridine-3-­carboxyl­ate ligands through the N atoms and carboxylate groups. One Na atom and one pyridine-3-­carboxyl­ate ligand lie on a twofold axis. Extensive Na coordination results in a three-dimensional array comprising infinite NaO₂CR chains linked by intrachain Na-N bonds.

The crystal structure of the title compound, C₁₁H₁₁NO₄, forms an extended inter­digitated hydrogen-bonded array via O—HO inter­actions parallel to the c axis. The oxime adopts a Z configuration.

The title compound, C₁₀H₁₆N₄O₃S, is the first example of a fused bicyclic oxathia­triaza­indene ring system The six-membered heterocycle adopts a boat conformation. Molecules are linked by weak C—HO hydrogen bonds.

The title compound, C₁₂H₁₈N₄O₃S, is the first example of a fused dicyclic hexa­hydro-4-oxa-5-thia-1,6,7a-triazaindene ring system. The structure comprises two mol­ecules in the asymmetric unit, which differ in terms of the orientation of their pendant n-propyl groups.

The title compound, C₁₀H₁₄N₄O₃S, is the first example of the fused tricyclic octahydro-1-thia-2,3a,8a-triazacyclopenta[a]indene ring system. The S-containing heterocycle adopts a typical envelope conformation, fused at the 2,3-positions to a 2,3a,4,5,6,7-hexa­hydro­indazol-3-one unit.

The title compound, [Zn₄(C₂₈H₁₈N₄O₂)₂(CH₃O)₂](ClO₄)₂·2C₃H₇NO, is a C2 symmetric tetra­nuclear zinc(II) complex comprised of two [Zn₂L]²⁺ units bridged by a pair of μ₂-OMe ligands (where L is the doubly-deprotonated form of the macrocyclic dinucleating ligand derived from the [2 + 2] Schiff base condensation between 2-hy­droxy­benzene-1,3-dicarbaldehyde and 1,2-diamino­benzene). Each Zn^II atom has a distorted square-pyramidal coordination geometry and the Zn₄(μ-OMe)₂ unit lies in the cleft formed by two distinctly bent Schiff base ligands. The observed mol­ecular shape is supported by an intra­molecular π–π inter­action between one of the phenolate rings on each of the two ligands [centroid–centroid distance = 3.491 (5) Å]. The methyl groups of the solvent molecule are disordered over two sets of sites in a 0.6:0.4 ratio.

In the trinuclear title compound, [Cu₃Cl₄(C₁₇H₃₈N₃O₂)₂]·2H₂O or [Cu(AcC₁₁tacn)Cl·H₂O]₂·CuCl₂ [tacn is 1,4,7-triaza­cyclo­nonone], two Cu atoms are coordinated by a bifunctionalized 1-acetato-4-undecyl-1,4,7-triaza­cyclo­nonone (AcC₁₁tacn) macrocycle and are five-coordinate, while the third Cu atom, located on a centre of inversion, bridges these two units between two keto O atoms, with two Cl atoms completing a four-coordinate square-planar geometry. The long C₁₁ tails on the macrocycle create well ordered multilayer packing.