Development of a time of flight spectrometer based on position sensitive multi-wire proportional counters for fission fragment mass distribution studies

Characteristics and performance of a time of flight (TOF) spectrometer developed for performing fission mass distribution studies are presented. The spectrometer contains two TOF arms based on multi-wire proportional counters (MWPCs). Each arm has two MWPCs to form a start-stop detection system for TOF measurements. The start detector has an active area of 4 × 4 cm². The stop detector is a two-dimensional position sensitive MWPC with an active area of 16 × 11 cm². Salient features of the MWPCs are the use of reduced sub-millimeter wire pitches of 0.635 and 0.317 mm in the electrodes along with the use of gold plated tungsten wires of diameters 10 and 20 µm. A delay line for position electrodes is prepared using chip inductors and capacitors. Ten different configurations of MWPC were investigated for the start detector, which involved the use of three and four electrode geometries, use of different wire pitches, and use of aluminized mylar for timing electrodes. Performance results close to micro-channel plate detectors have been observed with some designs of MWPC, displaying rise times better than 2 ns with an estimated inherent time resolution of ∼100 ps FWHM. A position resolution of ∼1 mm (FWHM) has been observed. Design features of the MWPCs and their test performance results are described in this article.

Efficient control of air pollution through plants, a cost-effective alternative: studies on Dalbergia sissoo Roxb

Plants can be used as both passive biomonitors and biomitigators in urban and industrial environments to indicate the environmental quality and to ameliorate pollution level in a locality. Many studies reveal that plants are negatively affected by the ambient levels of air pollutants. The present study was conducted to evaluate the impact of air pollution on comparative basis with reference to changes in photosynthetic pigments, plant height, leaves, as well as, biochemical parameters of plants of different sites around Udaipur city receiving varying levels of pollution load. The investigated tree species Dalbergia sissoo Roxb. (Family: Fabaceae) exhibited a reduction in various physiological and biochemical growth parameters that correspond with air pollution levels at different sites. The tree species growing in polluted and control areas were compared with respect to foliar dust load, leaf area, and chlorophyll and total carbohydrate and total protein concentration in the leaves. Our studies suggest that D. sissoo Roxb. can successfully be grown in an area for monitoring air pollution, where it is mild and droughts are common. It will prove as an ideal tree species to control pollution effectively beside acting as a shade tree and being a source of food for birds and animals. By plantation of D. sissoo Roxb., mitigative measure at the polluted sites to control generation of particulate matter and the air quality required can be ensured. Our results also confirm that industrial and vehicular air pollution level in Udaipur city is shifting beyond limits.

(R)-2-Cyano-N-(1-phenyl-eth-yl)acetamide

In the title compound, C₁₁H₁₂N₂O, the dihedral angle between the acetamide group and the benzene ring is 68.7 (1)°. In the crystal, N—H⋯O and weak C—H⋯O hydrogen bonds link the mol­ecules into chains along the a-axis direction.

5-Bromo-2-chloropyrimidin-4-amine

In the title compound, C₄H₃BrClN₃, the pyrimidine ring is essentially planar (r.m.s. deviation from the plane = 0.087 Å). In the crystal, pairs of N—H⋯N hydrogen bonds connect the mol­ecules into inversion dimers; these are connected by further N—H⋯N hydrogen bonds into a two-dimensional framework parallel to the bc plane.

Ethyl 2-(quinolin-8-yloxy)acetate monohydrate

In the title compound, C₁₃H₁₃NO₃·H₂O, the dihedral angle between the ethyl ester group [C—C—O—C(=O); maximum deviation = 0.003 (2) Å] and the quinoline ring system is 7.94 (12)°. The water solvent mol­ecule is linked to the title mol­ecule via O—H⋯O and O—H⋯N hydrogen bonds. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming chains propagating along [100].

2-[(Dimethylamino)methylidene]propanedinitrile

In the title moleclue, C₆H₇N₃, the mean plane of the dimethyl­amino group [maximum deviation = 0.006 (2) Å] forms a dihedral angle of 7.95 (18)° with the mean plane of the propane­dinitrile fragment [maximum deviation = 0.008 (2) Å]. In the crystal, weak C—H⋯N hydrogen bonds link the mol­ecules into a three-dimensional network.

2-Amino-7,7-dimethyl-5-oxo-4-[3-(trifluoromethyl)phenyl]-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile

In the title mol­ecule, C₁₉H₁₇F₃N₂O₂, the fused cyclo­hexene and pyran rings adopt sofa and flattened boat conformations, respectively. The four essentially planar atoms of the pyran ring [maximum deviation = 0.008 (2) Å] form a dihedral angle of 88.13 (9)° with the benzene ring. The F atoms of the trifluoro­methyl group were refined as disordered over three sets of sites in a 0.507 (7):0.330 (7):0.163 (3) ratio. In the crystal, mol­ecules are connected into inversion dimers via pairs of N—H⋯N hydrogen bonds and these dimers are further linked by N—H⋯O hydrogen bonds into a two-dimensional network parallel to (100).

Tubulin inhibitors from an endophytic fungus isolated from Cedrus deodara

From an endophytic fungus, a close relative of Talaromyces sp., found in association with Cedrus deodara, four compounds including two new ones (2 and 4) were isolated and characterized. The structures of two compounds (1 and 4) were confirmed by X-ray crystallography. The compounds displayed a range of cytotoxicities against human cancer cell lines (HCT-116, A-549, HEP-1, THP-1, and PC-3). All the compounds were found to induce apoptosis in HL-60 cells, as evidenced by fluorescence and scanning electron microscopy studies. Also, the compounds caused significant microtubule inhibition in HL-60 cells.

5-Benzoyl-4-(4-fluoro-phen-yl)-3,4-dihydro-pyrimidin-2(1H)-one

In the title mol-ecule, C(17)H(13)FN(2)O(2), the 3,4-dihydro-pyrimidine ring adopts a flattened sofa conformation with the flap atom (which bears the fluoro-phenyl substituent) deviating from the plane defined by the remaining five ring atoms by 0.281 (2) Å. This plane forms dihedral angles of 85.98 (6) and 60.63 (6)° with the 4-fluoro-phenyl and benzoyl-phenyl rings, respectively. The dihedral angle between the 4-fluoro-phenyl group and the benzene ring is 71.78 (6)°. In the crystal, N-H⋯O hydrogen bonds link mol-ecules into inversion dimers that are further connected by another N-H⋯O inter-action into a two-dimensional supra-molecular structure parallel to (101).

9-(3,4-Dimeth-oxy-phen-yl)-3,3,6,6-tetra-methyl-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridine-1,8-dione

The asymmetric unit of the title compound, C₂₅H₃₁NO₄, contains two independent mol­ecules. In one mol­ecule, the benzene ring and an attached meth­oxy group were refined as disordered over two sets of sites in a 0.65 (4): 0.35 (4) ratio. In both mol­ecules, the central ring of the acridinedione system adopts a flattened boat conformation. The four essentially planar atoms of this ring [maximum deviations = 0.006 (5) Å in both mol­ecules] forms dihedral angles of 86.8 (2) and 87.6 (2)°, respectively, with the major and minor components in the disordered benzene ring and 87.3 (2)° with the benzene ring in the fully ordered mol­ecule. The two outer rings of the acridinedione system adopt sofa conformations in both mol­ecules. In the crystal, N—H⋯O hydrogen bonds form two independent chains along [100]. C—H⋯O hydrogen bonds link the chains, forming a three-dimensional network.

2-Amino-7,7-dimethyl-5-oxo-4-[3-(trifluoromethyl)phenyl]-1,4,5,6,7,8-hexahydroquinoline-3-carbonitrile

In the title mol­ecule, C₁₉H₁₈F₃N₃O, the dihydro­pyridine and cyclo­hexene rings both adopt sofa conformations. The five essentially planar atoms of the dihydro­pyridine ring [maximum deviation = 0.039 (2) Å] form a dihedral angle of 88.19 (8)° with the benzene ring. The F atoms of the trifluoro­methyl group were refined as disordered over two sets of sites in a 0.840 (3):0.160 (3) ratio. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds link mol­ecules into a two-dimensional network parallel to (100).

A second monoclinic polymorph of 4-[(E)-(4-benzyl-oxybenzyl-idene)amino]-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one

In the title compound, C₂₅H₂₃N₃O₂, the central benzene ring makes dihedral angles of 77.14 (8) and 87.7 (2)° with the terminal benzene rings and an angle of 1.9 (1)° with the pyrazolone ring. The benzene ring and the N atom of the pyrazole ring bearing the phenyl substituent are disordered over two sets of sites with an occupancy ratio of 0.71 (2):0.29 (2). The N atoms of the pyrazole ring have a pyramidal environment, the sums of the valence angles around them being 354.6 (3) and 352.0 (6)/349.5 (15)°. In the crystal, mol­ecules are packed into layers parallel to the ac plane. The other monoclinic polymorphic form was reported recently [Dutkiewicz et al. (2012 ▶). Acta Cryst. E68, o1324].

9-(4-Hy-droxy-3-meth-oxy-phen-yl)-3,3,6,6-tetra-methyl-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridine-1,8-dione

In the title mol-ecule, C24H29NO4, the central ring of the acridinedione system adopts a flat boat conformation and the four essentially planar atoms of this ring [maximum deviation = 0.001 (2) Å] form a dihedral angle of 85.99 (12)° with the benzene ring. The two outer rings of the acridinedione system adopt sofa conformations. In the crystal, O-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules, forming a two-dimensional network parallel to (100).

9-(3-Fluoro-phen-yl)-3,3,6,6-tetra-methyl-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridine-1,8-dione

In the title mol-ecule, C23H26FNO2, the central ring of the acridinedione system adopts a slight boat conformation and the four essentially planar atoms of this ring [maximum deviation = 0.019 (1) Å] form a dihedral angle of 89.98 (6)° with the benzene ring. The two outer rings of the acridinedione system adopt sofa conformations. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules, forming chains along [001].

Synthesis, characterization and X-ray structure of the adducts of bis(O-butyldithiocarbonato)nickel(II) with substituted pyridines

Some mixed ligand complexes of Ni(II) with O-butyldithiocarbonate as a primary ligand and substituted pyridines as secondary ligands have been isolated and characterized on the basis of analytical data, molar conductance, magnetic susceptibility, electronic and infrared spectral studies. The molar conductance studies show their non-electrolytic behavior. Magnetic and electronic spectral studies suggest octahedral stereochemistry around Ni(II) ions. Infrared spectral studies suggest bidentate chelating behavior of O-butyldithiocarbonate monoanion while other ligands show unidentate behavior in their complexes. One of the adduct bis(O-butyldithiocarbonato)bis(3,5-dimethylpyridine)nickel(II) crystallizes in the monoclinic space group P21/c with unit cell parameters. The crystal structure has been solved by direct methods and refined by full matrix least-squares procedures to a final R-value of 0.0379 for 2460 observed reflections. The Ni2+ ion is in a octahedral coordination environment formed by an N2S4 donor set, defined by two chelating dithiocarbonate anions as well as two 3,5-dimethylpyridine ligands with the Ni2+ ion located at the inversion centre. The packing of layers of molecules is stabilized by weak pi-pi and C-H---pi interactions.

3-Methoxy-2-[2-({[6-(trifluoromethyl)pyridin-2-yl]oxy}methyl)phenyl]prop-2-enoic acid

The title mol­ecule, C₁₇H₁₄F₃NO₄, consists of two nearly planar fragments, viz. the 2-benzyl­oxypyridine (r.m.s. deviation 0.016 Å) and (E)-3-meth­oxy­prop2-enoic (r.m.s. deviation 0.004 Å) units, which form a dihedral angle of 84.19 (7)°. In the crystal, pairs of O—H⋯O hydrogen bonds link mol­ecules into dimers that are further connected by C—H⋯O and C—H⋯F inter­actions into (001) layers. In addition, π–π stacking inter­actions are observed within a layer between the pyridine and benzene rings [centroid–centroid distance = 3.768 (2) Å]. The F atoms of the trifluoro­methyl group are disordered over two sets of sites in a 0.53 (4):0.47 (4) ratio.

Methyl (2E)-2-cyano-3-(dimethylamino)prop-2-enoate

In the title compound, C₇H₁₀N₂O₂, the dimethyl­amino group is twisted slightly relative to the acrylate fragment, forming a dihedral angle of 11.6 (1)°. In the crystal, molecules are linked via pairs of bifurcated C—H/H⋯O hydrogen bonds, forming inversion dimers, which are further connected by C—H⋯N hydrogen bonds into chains along the a-axis direction.

N-(4-Chloro-phen-yl)-4-meth-oxy-benzamide

In the title compound, C₁₄H₁₂ClNO₂, the mean plane through the amide group [–N—C=O–] forms dihedral angles of 27.55 (8) and 31.94 (7)° with the meth­oxy- and chloro-substituted benzene rings, respectively. The dihedral angle between the benzene rings is 59.24 (4)°. In the crystal, N—H⋯O and weak C—H⋯O hydrogen bonds link the mol­ecules into chains along the a axis.

N-(2-{[5-Bromo-2-(piperidin-1-yl)pyrimidin-4-yl]sulfan-yl}-4-meth-oxy-phen-yl)benzene-sulfonamide

The title compound, C₂₂H₂₃BrN₄O₃S₂, crystallizes with two mol­ecules, A and B, in the asymmetric unit. In one of these, the meth­oxy group is disordered over two sets of sites in a 0.565 (9):0.435 (9) ratio. The benzene rings bridged by the sulfonamide group are tilted relative to each other by 37.4 (1) and 56.1 (1)° in mol­ecules A and B, respectively, while the dihedral angles between the sulfur-bridged pyrimidine and benzene rings are 72.4 (1) and 70.2 (1)° for A and B, respectively. The piperidine ring adopts a chair conformation in both mol­ecules. In the crystal, inversion dimers linked by pairs of N—H⋯N hydrogen bonds occur for both A and B; the dimers are linked into [010] chains by C—H⋯O hydrogen bonds. The crystal structure also features inversion-generated aromatic π–π stacking inter­actions between the pyrimidine rings for both mol­ecules [centroid–centroid distances = 3.412 (2) (mol­ecule A) and 3.396 (2) Å (mol­ecule B)].

(2E)-3-(Dimethyl-amino)-1-(4-fluoro-phen-yl)prop-2-en-1-one

In the title compound, C(11)H(12)FNO, the dihedral angle between the prop-2-en-1-one group and the benzene ring is 19.33 (6)°. The configuration of the keto group with respect to the olefinic double bond is s-cis. In the crystal, the mol-ecules form dimers through aromatic π-π stacking inter-actions [centroid-centroid distance = 3.667 (1) Å] and are linked via C-H⋯O inter-actions into chains along the b axis.

N-[2-(5-Bromo-2-morpholin-4-ylpyrim-idin-4-ylsulfan-yl)-4-meth-oxy-phen-yl]-2,4,6-trimethyl-benzene-sulfonamide

In the title compound, C(24)H(27)BrN(4)O(4)S(2), the mol-ecule is twisted at the sulfonyl S atom with a C-S(O(2))-N(H)-C torsion angle of 62.6 (3)°. The benzene rings bridged by the sulfonamide group are tilted to each other by a dihedral angle of 60.6 (1)°. The dihedral angle between the sulfur-bridged pyrimidine and benzene rings is 62.7 (1)°. The morpholine ring adopts a chair conformation. The mol-ecular conformation is stabilized by a weak intra-molecular π-π stacking inter-action between the pyrimidine and the 2,4,6-trimethyl-benzene rings [centroid-centroid distance = 3.793 (2) Å]. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into a chain along the b axis.

3-[(2-Chloro-1,3-thia-zol-5-yl)meth-yl]-5-methyl-1,3,5-oxadiazinan-4-one

In the title compound, C(8)H(10)ClN(3)O(2)S, the oxadiazinane ring is in a sofa conformation with the ring O atom deviating from the best plane of the remaining five atoms by 0.636 (2) Å. A short intra-molecular C-S⋯O=C contact [S⋯O 3.122 (2) Å, C-S⋯O 80.0 (2)°] is observed between the two mol-ecular fragments bridged by the methyl-ene group. In the crystal, C-H⋯O hydrogen bonds link mol-ecules, forming chains along the b axis.

N-[2-({[1-(4-Chlorophenyl)-1H-pyrazol-3-yl]oxy}methyl)phenyl]-N-methoxyhydrazinecarboxamide

In the title compound, C₁₈H₁₈ClN₅O₃, the hydrazinecarboxamide N—N—C(O)—N unit is nearly planar [maximum deviation = 0.074 (2) Å] and is inclined at a dihedral angle of 57.43 (7)° with respect to the plane of the attached benzene ring. The chloro­phenyl group makes dihedral angles of 19.71 (7) and 34.07 (6)° with the pyrazole and benzene rings, respectively. In the crystal, pairs of N—H⋯O hydrogen bonds link the mol­ecules into inversion dimers that are further linked into chains along the a-axis direction by N—H⋯N hydrogen bonds. In addition, π–π stacking inter­actions are observed between benzene rings [centroid–centroid distance = 3.680 (1) Å].

N-(2-{[5-Bromo-2-(piperidin-1-yl)pyrimidin-4-yl]sulfanyl}-4-methoxyphenyl)-4-methylbenzenesulfonamide

In the title compound, C₂₃H₂₅BrN₄O₃S₂, the benzene rings bridged by the sulfonamide group are tilted relative to each other by 69.7 (1)° and the dihedral angle between the sulfur-bridged pyrimidine and benzene rings is 70.4 (1)°. The mol­ecular conformation is stabilized by a weak intra­molecular π–π stacking inter­action between the pyrimidine and the 4-methyl benzene rings [centroid–centroid distance = 3.633 (2) Å]. The piperidine ring adopts a chair conformation. In the crystal, mol­ecules are linked into inversion dimers by pairs of N—H⋯O hydrogen bonds.

N'-[(E)-4-Hy-droxy-benzyl-idene]-2-(naph-tha-len-2-yl-oxy)acetohydrazide

The asymmetric unit of the title compound, C₁₉H₁₆N₂O₃, contains two independent mol­ecules in which the dihedral angles between the naphthalene ring system and the benzene ring are 10.0 (1) and 35.3 (1)°. In the crystal, mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds, forming a two-dimensional framework parallel to (001). Weak C—H⋯O and C—H⋯N hydrogen bonds complete a three-dimensional network.

N-(2-{[5-Bromo-2-(piperidin-1-yl)pyrimidin-4-yl]sulfanyl}-4-methoxyphenyl)-2,4,6-trimethylbenzenesulfonamide

In the title compound, C₂₅H₂₉BrN₄O₃S₂, the benzene rings bridged by the sulfonamide group are tilted relative to each other by 63.9 (1)° and the dihedral angle between the sulfur-bridged pyrimidine and benzene rings is 64.9 (1)°. The mol­ecular conformation is stabilized by a weak intra­molecular π–π stacking inter­action between the pyrimidine and the 2,4,6-trimethyl­benzene rings [centroid–centroid distance = 3.766 (2) Å]. The piperidine ring adopts a chair conformation. In the crystal, mol­ecules are linked into inversion dimers by pairs of N—H⋯O hydrogen bonds and these dimers are further linked by C—H⋯O hydrogen bonds into chains propagating along [010].

Ethyl 6-(4-bromo-phen-yl)-4-(4-fluoro-phen-yl)-2-oxocyclo-hex-3-ene-1-carboxyl-ate

There are two independent mol­ecules in the asymmetric unit of the title compound, C₂₁H₁₈BrFO₃, in which the dihedral angles between the fluoro­phenyl and bromo­phenyl groups are 77.0 (1) and 85.8 (1)°. In one of the mol­ecules, two methine C—H groups of the cyclo­hexene ring are disordered over two sets of sites in a 0.53 (2):0.47 (2) ratio. In both mol­ecules, the atoms of the ethyl group were refined as disordered over two sets of sites with occupancies of 0.67 (2):0.33 (2) and 0.63 (4):0.37 (4). The cyclo­hexene rings have slightly distorted sofa conformations in both mol­ecules. In the crystal, C—H⋯O inter­actions link mol­ecules into chains along the b axis.

N-(2-{[5-Bromo-2-(morpholin-4-yl)pyrimidin-4-yl]sulfan-yl}-4-meth-oxy-phen-yl)-4-chloro-benzene-sulfonamide

In the title compound, C₂₁H₂₀BrClN₄O₄S₂, the benzene rings bridged by the sulfonamide group are tilted relative to each other by a dihedral angle of 70.2 (1)° and the dihedral angle between the sulfur-bridged pyrimidine and benzene rings is 69.5 (1)°. The mol­ecular conformation is stabilized by a weak intra­molecular π–π stacking inter­action between the pyrimidine and the 4-chloro­benzene rings [centroid–centroid distance = 3.978 (2) Å]. The morpholine ring adopts a chair conformation. In the crystal, mol­ecules are linked into inversion dimers by pairs of C—H⋯N hydrogen bonds and these dimers are further connected by N—H⋯O hydrogen bonds, forming a tape along the a axis.

2-Meth-oxy-imino-2-{2-[(2-methyl-phen-oxy)meth-yl]phen-yl}ethanol

In the title compound, C(17)H(19)NO(3), the dihedral angle between the benzene rings is 68.0 (1)°. The C-O-C-C torsion angle of the atoms joining these rings is 179.7 (2)°. The atoms of the methanol group were refined as disordered over two sets of sites with fixed occupancies of 0.86 and 0.14. The H atoms of the hy-droxy group in the major component are disordered over a further two sets of sites with equal occupancies. This is a necessary arrangement to allow for hydrogen bonding without unrealistic H⋯H contacts. In the crystal, O-H⋯N and O-H⋯O hydrogen bonds connect mol-ecules into chains along [001].

(2E)-1-(4,4''-Difluoro-5'-meth-oxy-1,1':3',1''-terphenyl-4'-yl)-3-[4-(methyl-sulfan-yl)phen-yl]prop-2-en-1-one

In the title compound, C(29)H(22)F(2)O(2)S, the central benzene ring makes dihedral angles of 45.83 (7), 38.90 (7) and 55.50 (7)° with the two fluoro-substituted benzene rings and the methyl-sulfanyl-substituted benzene ring, respectively. In the crystal, C-H⋯O contacts connect the mol-ecules into layers lying perpendicular to the c axis. In addition, π-π stacking inter-actions between one of the fluoro-phenyl groups [centroid-centroid distances = 3.681 (1) and 3.818 (1) Å] are observed.

1,2,3,4,5,6-Hexa-O-acetyl-scyllo-inositol

The title mol­ecule, C₁₈H₂₄O₁₂, has crystallographic 2/m symmetry with two acetate group located on a mirror plane. The H—Csp³—O—Csp² torsion angles characterizing orientation of the acetyl groups with respect to the cyclo­hexane ring are 0.0, 23.9 and −23.9°. The cyclo­hexane ring is in a chair conformation with all substituents in equatorial positions. In the crystal, mol­ecules are connected through C—H⋯O hydrogen bonds into a chain extending along the c axis.