The asymmetric unit of the title chalcone derivative, C(19)H(20)ClNO, contains two independent mol-ecules, which differ in the conformations of the ethyl groups in the diethyl-amino substituents. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link mol-ecules into ribbons propogating in [010]. The crystal packing also exhibits weak C-H⋯π inter-actions.

The mol-ecule of the title compound, C(8)H(13)NO(6), a sucrose derivative, consists of two fused tetra-hydro-furan rings having the cis arrangement at the ring junctions, giving a V-shaped mol-ecule. An intra-molecular O-H⋯O inter-action occurs. Inter-molecular O-H⋯O hydrogen bonds help to stabilize the crystal structure.

In the title compound, C(11)H(12)N(2)O(2), a benzodiazepine derivative, the seven-membered ring adopts a distorted boat conformation. The crystal packing is controlled by inter-molecular N-H⋯O and C-H⋯O inter-actions.

The title compound, C(12)H(15)ClN(2)O, is a piperazine derivative with the potential for use as a starting material for pharmaceutial and agrochemical applications. The structure is stabilized by C-H⋯O hydrogen bonds, C-H⋯π inter-actions and π-π stacking inter-actions [centroid-centroid distance = is 4.760 (2) Å].

The title coumarin derivative, C20H14N2O3, displays intra-molecular N-H⋯O and weak C-H⋯O hydrogen bonds, which probably contribute to the approximate planarity of the mol-ecule [dihedral angle between the coumarin and quinoline ring systems = 6.08 (6)°]. The supra-molecular structures feature C-H⋯O hydrogen bonds and π-π inter-actions, as confirmed by Hirshfeld surface analyses.

Mol-ecules of the title spiro-[4.5]decane derivative, C(17)H(30)N(2)O(3)S, are linked by paired O-H⋯N hydrogen bonds into centrosymmetric R(2) (2)(16) dimers and these dimers are linked into a three-dimensional framework structure by C-H⋯O interactions.

The title compound, C(21)H(19)ClN(2)O(5), is a tetra-substituted hydantoin derivative which contains an imidazolidine-2,4-dione core. The dihedral angle between the aromatic rings is 64.53 (14)°. In the crystal, weak inter-molecular C-H⋯O hydrogen bonding is found. An intra-molecular C-H⋯O inter-action also occurs.

Bisadduct isomers of a H(2)@C(60) derivative with nitroxide addends have been synthesized, isolated and characterized. The (1)H NMRs of endohedral H(2) of the major isomers show well-separated chemical shifts, which could be useful for structural assignment and identification of the purity of the C(60) bisadduct isomers.

In the title compound, C(12)H(14)O(4), a derivative of caffeic acid [(E)-3-(3,4-dihy-droxy-phen-yl)-2-propenoic acid], an intra-molecular O-H⋯O hydrogen bond forms an S(5) ring. In the crystal, inter-molecular O-H⋯O hydrogen bonds link mol-ecules into chains propagating in [110].

The title compound, C(6)H(10)N(2)O, is a zwitterionic pyrazole derivative. The crystal packing is predominantly governed by a three-center iminium-amine N(+)-H⋯O(-)⋯H-N inter-action, leading to an undulating sheet-like structure lying parallel to (100).