1,099 research outputs found
Phosphorus recovery: a need for an integrated approach
Increasing cost of phosphate fertilizer, a scarcity of high quality phosphate rock (PR)and increasing surface water pollution are driving aneed to accelerate the recovery and re-use ofphosphorus (P) from various waste sectors. Options to recover P occur all along the open P cycle from mining to households to oceans. However, P recovery as a regional and global strategy towards P sustainability and future food, bio energy and water security is in its infancy because of a number of technological, socio-economic and institutional constraints. There is no single solution and resolving these constraints requires concerted collaboration betweenrelevant stakeholders and an integrated approach combiningsuccessful business models withsocio-economic and institutional change. We suggest that an operational framework is developed for fast tracking cost-effective recovery options
(E)-2-[(2-Hydroxy-5-nitrophenyl)iminiomethyl]-4-nitrophenolate
The title molecule, C13H9N3O6, consists of a 2-hydroxy-5-nitrophenyliminio group and a 4-nitrophenolate group bonded to a methylene C atom with both of the planar six-membered rings nearly in the plane of the molecule [dihedral angle = 1.3 (4)°]. Each of the nitro O atoms is twisted slightly out of the plane of the molecule. The amine group forms an intramolecular hydrogen bond with both nearby O atoms, each of which has partial occupancy of attached H atoms [0.36 (3) and 0.64 (3)]. An extended π-delocalization throughout the entire molecule exists producing a zwitterionic effect in this region of the molecule. The shortened phenolate C—O bond [1.2749 (19)°], in concert with the slightly longer phenol C—O bond [1.3316 (19) Å], provides evidence for this effect. The crystal packing is influenced by extensive strong intermolecular O—H⋯O hydrogen bonding between the depicted phenolate and hydroxy O atoms and their respective H atoms within the π-delocalized region of the molecule. As a result, molecules are linked into an infinite polymeric chain diagonally along the [110] plane of the unit cell in an alternate inverted pattern. A MOPAC AM1 calculation provides support for these observations
Methyl 1-benzyl-5-methyl-2,4-diphenyl-1H-pyrrole-3-carboxyl-ate
In the title compound, C26H23NO2, the dihedral angles between the pyrrole ring and the two phenyl rings are 58.1 (6) and 71.5 (5)°. The mean planes of the 5-methylbenzene ring and the carboxyl group are twisted by 89.5 (3) and 22.1 (9)°, respectively, from the pyrrole ring. In the crystal, weak C—H⋯O interactions lead to supramolecular layers in the ab plane
(E)-2-[(2-Hydroxy-5-nitrophenyl)iminiomethyl]phenolate
In the title molecule, C13H10N2O4, the dihedral angle between the mean planes of the benzene and phenolate rings is 21.6 (4)°. The nitro O atoms are twisted slightly out of the plane of the ring to which the nitro group is attached [dihedral angle 8.4 (3)°]. The amine group forms an intramolecular hydrogen bond with both nearby O atoms. An extended π delocalization throughout the entire molecule exists producing a zwitterionic effect in this region of the molecule. The shortened C—O bond [1.2997 (15) Å] in concert with the slightly longer C—OH bond [1.3310 (16) Å] provide evidence for this effect. The crystal packing is influenced by strong intermolecular O—H⋯O hydrogen bonding. As a result, molecules are linked into an infinite zigzag chain running along the b axis. A MOPAC PM3 calculation provides support to these observations
N 1,N 2-Bis[(2-chloro-6-methylquinolin-3-yl)methylidene]ethane-1,2-diamine
The title molecule, C24H20Cl2N4, lies on an inversion center in an extended trans conformation. In the crystal, weak C—H⋯Cl interactions connect the molecules into chains along [010]
Opipramolium fumarate
In the crystal structure of the title salt {systematic name: 4-[3-(5H-dibenz[b,f]azepin-5-yl)propyl]-1-(2-hydroxyethyl)piperazin-1-ium (2Z)-3-carboxyprop-2-enoate}, C23H30N3O+·C4H3O4
−, the piperazine group in the opipramol cation is protonated at only one of the N atoms. In the cation, the dihedral angle between the two benzene rings is 53.5 (6)°. An extensive array of intermolecular O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds and weak intermolecular N—H⋯O, C—H⋯O and C—H⋯π interactions dominate the crystal packing
Enrofloxacinium picrate
There is one cation–anion pair in the asymmetric unit of the title compound [systematic name: 4-(3-carboxy-6-fluoro-4-oxo-1,4-dihydroquinolin-7-yl)-1-ethylpiperazin-1-ium 2,4,6-trinitrophenolate], C19H23FN3O3
+·C6H2N3O7
−. The six-membered piperazine group in the cation adopts a slightly distorted chair conformation and contains a protonated N atom. The dihedral angles between the mean planes of the cyclopropyl and piperazine rings in the cation with the 10-atom ring system of the quinolone group are 48.1 (1) and 69.9 (5)°, respectively. The picrate anion interacts with the protonated N atom of an adjacent cation through a bifurcated N—H⋯O three-center hydrogen bond, forming an R
1
2(6) ring motif. Furthermore, there is an intramolecular O—H⋯O hydrogen bond. The dihedral angle between the mean planes of the anion benzene and cation piperizine, quinoline and cyclopropyl rings are 61.3 (6), 31.1 (4) and 70.4 (9)°, respectively. The mean planes of the two o-NO2 and single p-NO2 groups in the picrate anion are twisted by 6.7 (6), 38.3 (9) and 12.8 (7)° with respect to the mean plane of the benzene ring. Strong N—H⋯O and weak intermolecular C—H⋯O hydrogen bonds in concert with weak π–π stacking interactions [centroid–centroid distances = 3.5785 (13), 3.7451 (12) and 3.6587 (13) Å] dominate the crystal packing
Imatinibium dipicrate
In the crystal structure of imatinibium dipicrate [systematic name: 1-methyl-4-(4-{4-methyl-3-[4-(3-pyridyl)pyrimidin-2-ylamino]anilinocarbonyl}benzyl)piperazine-1,4-diium dipicrate], C29H33N7O2+·2C6H2N3O7
−, the imatinibium cation is protonated at both of the pyrimidine N atoms. Each of the two picrate anions interacts with the diprotonated cation through bifurcated N—H⋯O hydrogen bonds forming R
1
2(6) ring motifs. Also, an R
2
2(24) graph set is formed between the benzamidium –NH– group and the 4-pyridyl N atom interacting through N—H⋯N hydrogen-bond interactions. Additional weak C—H⋯Cg π-ring and π–π intermolecular interactions are observed which also influence crystal packing
9-[3-(Dimethylamino)propyl]-2-trifluoromethyl-9H-thioxanthen-9-ol
In the title compound, C19H20F3NOS, the dihedral angle between the mean planes of the two benzene rings attached to the thioxanthene ring is 41.8 (7)°; the latter has a slightly distorted boat conformation. The F atoms are disordered over three sets of sites [occupancy ratio = 0.564 (10):0.287 (10):0.148 (5)] and the methyl groups are disordered over two sets of sites [occupancy ratio = 0.72 (4):0.28 (4)]. The crystal packing is stabilized by O—H⋯N and C—H⋯S hydrogen bonds and weak C—H⋯Cg interactions
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