The asymmetric unit of the title cyclic thio-urea derivative, C10H12N2S, comprises two mol-ecules, each of which has a twist about the CH2-CH2 bond within the five-membered ring. The major difference between the independent mol-ecules is manifested in the relative orientations of the five- and six-membered rings [dihedral angles between the least-squares planes = 28.03 (11) and 41.54 (11)°]. A network of C-H⋯π inter-actions consolidates the three-dimensional crystal packing.
Baeckea frutescens or locally known as Cucur atap is used as antibacterial, antidysentery, antipyretic and diuretic agent. In Malaysia and Indonesia, they are used as an ingredient of the traditional medicine given to mothers during confinement. A three-steps infra-red (IR) macro-fingerprinting method combining conventional IR spectra, and the secondary derivative spectra with two dimensional infrared correlation spectroscopy (2D-IR) have been proved to be effective methods to examine a complicated mixture such as herbal medicines. This study investigated the feasibility of employing multi-steps IR spectroscopy in order to study the main constituents of B. frutescens and its different extracts (extracted by chloroform, ethyl acetate, methanol and aqueous in turn). The findings indicated that FT-IR and 2D-IR can provide many holistic variation rules of chemical constituents. The structural information of the samples indicated that B. frutescens and its extracts contain a large amount of flavonoids, since some characteristic absorption peaks of flavonoids, such as ∼1600cm(-1), ∼1500cm(-1), ∼1450cm(-1), and ∼1270cm(-1) can be observed. The macroscopical fingerprint characters of FT-IR and 2D-IR spectra can not only provide the information of main chemical constituents in medicinal materials and their different extracts, but also compare the components differences among the similar samples. In conclusion, the multi-steps IR macro-fingerprint method is rapid, effective, visual and accurate for pharmaceutical research.
In the crystal structure of the title compound, C(18)H(12)N(2)O, the dihedral angle between the two fused-ring systems is 84.3 (1) °; the C-O-C angle at the ether O atom is 117.31 (18)°.
There are two molecules in the asymmetric unit of the title compound, C(10)H(9)N(3), with inter-ring dihedral angles of 31.1 (1) and 35.3 (1)°. The bridging C-N-C bond angles are 128.2 (1) and 129.1 (1)°. In the crystal, the two independent mol-ecules are linked into a dimer by two N-H⋯N hydrogen bonds.
In the crystal structure of the title compound, [Cu(2)(C(2)H(3)O(2))(4)(C(12)H(12)N(2))(2)], the binuclear mol-ecule lies about a center of inversion; the four acetate groups each bridge a pair of Cu(II) atoms. The coordination of the metal atom is distorted square-pyramidal, with the bonding O atoms comprising a square basal plane and the coordinating N atom of the N-heterocycle occupying the apical position. The pyridine ring is twisted with respect to the benzene ring at a dihedral angle of 45.68 (16)°. Intra-molecular N-H⋯O hydrogen bonding is present between the imino and carb-oxy groups.
In the title compound, C(14)H(10)N(2)O, the organic rings are inclined at an angle of 86.1 (1)°. The angle at the ether O atom is widened to 117.18 (14)°.
In the title compound, C(11)H(9)ClN, the dihedral angle between the aromatic ring planes is 44.2 (1)° and the bridging C-N-C bond angle is 127.60 (19)°. The amino N-H grouping makes a hydrogen bond to the pyridyl N atom of an adjacent mol-ecule across a center of inversion, generating a hydrogen-bonded dimer.
There are two mol-ecules in the asymmetric unit of the title compound, C(14)H(10)N(2)O: the dihedral angles between their aromatic ring planes are 47.4 (4) and 46.8 (3)°. In the crystal structure, mol-ecules are linked by N-H⋯N hydrogen bonds from the secondary nitro-gen N-H donor to the tertiary N-atom acceptor of a symmetry-related neighbour, resulting in hydrogen-bonded chains. The two independent chains both propagate in [100].
A flow injection (FI) method with on-line preconcentration using a mini-column loaded with 8-hydroxyquinoline immobilized on controlled pore glass (CPG-8HQ) is described for the determination of trace metals by ion chromatography (IC) with pyridine-2-6-dicarboxylic acid (PDCA) as the eluent. Copper, cadmium, lead, zinc, nickel and iron were determined at ppb level after post-column derivatization with 4-(2-pyridylazo)-resorcinol (PAR). The detection limits (3sigma) for the FI/IC system were 8.27, 0.89, 0.09, 0.06, 0.09 and 0.07 g l(-1) for Pb(2+), Cd(2+), Cu(2+) Ni(2+), Zn(2+) and Fe(3+), respectively, using 5 ml sample volume. The method was applied to the analysis of Malaysian natural waters.
Two seco-tabersonine alkaloids, jerantiphyllines A and B, in addition to a tabersonine hydroxyindolenine, jerantinine H, and a recently reported vincamine alkaloid 7, were isolated from the leaf extract of the Malayan Tabernaemontana corymbosa and the structures were established using NMR and MS analysis. Biomimetic conversion of jerantinines A and E to their respective vincamine and 16-epivincamine derivatives were also carried out.
Two independent mol-ecules comprise the asymmetric unit in the title compound, C(11)H(11)N(3). These differ in terms of the relative orientations of the aromatic rings: the first is somewhat twisted, while the second is approximately planar [dihedral angles between the pyrimidine and phenyl rings = 39.00 (8) and 4.59 (11)°]. The mol-ecules also form distinct patterns in their hydrogen bonding. The first independent mol-ecule forms centrosymmetric dimers featuring an eight-membered {HNCN}(2) synthon. The second independent mol-ecule forms an N-H⋯N hydrogen bond with the other pyrimidine N atom of the first mol-ecule. Thereby, tetra-meric aggregates are formed. These associate via C-H⋯N and C-H⋯π inter-actions, consolidating the crystal packing.
In the title compound, C(13)H(14)N(2), the dihedral angle between the aromatic rings is 48.1 (1)° and the bridging C-N-C bond angle is 127.24 (12)°. In the crystal, intermolecular N-H⋯N hydrogen bonding about a center of inversion generates a hydrogen-bonded dimer.
In the crystal structure of the title binuclear complex, [Cu(2)(CH(3)COO)(4)(C(13)H(14)N(2))(2)], the four acetate groups each bridge a pair of Cu(II) atoms. The coordination of the metal atoms is distorted square-pyramidal, with the bonding O atoms comprising a square basal plane and the coordinating N atom of the N-heterocycle occupying the apical position. In the two N-hetercycle ligands, the benzene rings are twisted with respect to the pyridine rings, making dihedral angles of 53.1 (2) and 54.2 (2)°. Intra-molecular N-H⋯O hydrogen bonding is present between the imino and carb-oxy groups. The crystal studied was a non-merohedral twin with a minor twin component of 21.4%.
There are two mol-ecules in the asymmetric unit of the title compound, C(12)H(12)N(2), with dihedral angles between the aromatic rings of 48.35 (12) and 51.02 (12)°. In the crystal structure, both mol-ecules form inversion dimers, linked by pairs of N-H⋯N hydrogen bonds.
The dihedral angle between the two aromatic ring systems in the title compound, C(15)H(12)N(2)O, is 42.6 (1)°. The angle at the O atom is widened to 117.7 (1)°.
The dihedral angle between the two aromatic ring systems in the title compound, C(15)H(12)N(2)O, is 79.4 (1)°. The angle at the O atom is widened to 116.93 (9)°.
The dihedral angle between the two aromatic ring systems in the title compound, C(15)H(12)N(2)O, is 85.9 (1)°; The angle at the O atom is widened to 118.2 (2)°. The quinoxalin-yloxy part of the mol-ecule lies on a mirror plane and the tolyl group is disordered over two positions about the mirror plane.
The aromatic ring systems in the title compound, C(14)H(10)N(2)O, form a dihedral angle of 63.8 (1)°, resulting in an opening up of the ether-O atom angle to 118.2 (1)°.