Calcium l-Malate and d-Tartarate Frameworks as Adjuvants for the Sustainable Delivery of a Fungicide.

Agrichemical adjuvants that combine a highly selective, efficient, and active mode of operation are critically needed to realize a more sustainable approach to their usage. Herein, we report the synthesis and full characterization of two new metal-organic frameworks (MOFs), termed UPMOF-1 and UPMOF-2, that were constructed from eco-friendly Ca2+ ions and naturally occurring, low-molecular weight plant acids, l-malic and d-tartaric acid, respectively. Upon structural elucidation of both MOFs, a widely used fungicide, hexaconazole (Hex), was loaded on the structures, reaching binding affinities of -5.0 and -3.5 kcal mol-1 and loading capacities of 63% and 62% for Hex@UPMOF-1 and Hex@UPMOF-2, respectively, as a result of the formation of stable host-guest interactions. Given the framework chemistry of the MOFs and their predisposition to disassembly under relevant agricultural conditions, the sustained release kinetics were determined to show nearly quantitative release (98% and 95% for Hex@UPMOF-1 and Hex@UPMOF-2, respectively) after >500 h, a release profile drastically different than the control (>80% release in 24 h), from which the high efficiency of these new systems was established. To confirm their high selectivity and activity, in vitro and in vivo studies were performed to illustrate the abilities of Hex@UPMOF-1 and Hex@UPMOF-2 to combat the known aggressive pathogen Ganoderma boninense that causes basal stem rot disease in oil palm. Accordingly, at an extremely low concentration of 0.05 µg mL-1, both Hex@UPMOF-1 and Hex@UPMOF-2 were demonstrated to completely inhibit (100%) G. boninense growth, and during a 26 week in vivo nursery trial, the progression of basal stem rot infection was completely halted upon treatment with Hex@UPMOF-1 and Hex@UPMOF-2 and seedling growth was accelerated given the additional nutrients supplied via the disassembly of the MOFs. This study represents a significant step forward in the design of adjuvants to support the environmentally responsible use of agrichemical crop protection.

Synthesis, characterization and evaluation of antidengue activity of enantiomeric Schiff bases derived from S-substituted dithiocarbazate.

A series of Schiff bases have been successfully synthesized through the acid-catalyzed condensation of S-substituted dithiocarbazates and three enantiomerically pure monoterpenes, (1 R )-(+)-camphor, (1 S )-(-)-camphor, (1 R )-(-)-camphorquinone, (1 S )-(+)-camphorquinone, ( R )-(-)-carvone and ( S )-(+)-carvone. Spectroscopic results revealed that the Schiff bases containing camphor or carvone likely adopted an E -configuration along the characteristic imine bond while those containing camphorquinone assumed a Z -configuration. The antidengue potential of these compounds was evaluated based on DENV 2 caused cytopathic effect (CPE) reduction-based in vitro evaluation. The compounds were validated through secondary foci forming unit reduction assay (FFURA). Compounds were also tested for their cytotoxicity against Vero cells. The compounds showed variable degrees of antiviral activity with the camphor compounds displaying the highest antidengue potential. The enantiomers of the compounds behaved almost similarly during the antiviral evaluation.

Crystal structure of benzyl N'-[(1E,4E)-1,5-bis-(4-meth-oxy-phen-yl)penta-1,4-dien-3-yl-idene]hydrazine-1-carbodi-thio-ate.

In the title hydrazinecarbodi-thio-ate derivative, C27H26N2O2S2, the asymmetric unit is comprised of four mol-ecules (Z = 8 and Z' = 4). The 4-meth-oxy-phenyl rings are slightly twisted away from their attached olefinic double bonds [torsion angles = 5.9 (4)-19.6 (4)°]. The azomethine double bond has an s-trans configuration relative to one of the C=C bonds and an s-cis configuration relative to the other [C=C-C= N = 147.4 (6)-175.7 (2) and 15.3 (3)-37.4 (7)°, respectively]. The torsion angles between the azomethine C=N double bond and hydrazine-1-carbodi-thio-ate moiety indicate only small deviations from planarity, with torsion angles ranging from 0.9 (3) to 6.9 (3)° and from 174.9 (3) to 179.7 (2)°, respectively. The benzyl ring and the methyl-enesulfanyl moiety are almost perpendicular to each other, as indicated by their torsion angles [range 93.7 (3)-114.6 (2)°]. In the crystal, mol-ecules are linked by C-H⋯O, N-H⋯S and C-H⋯π(ring) hydrogen-bonding inter-actions into a three-dimensional network. Structural details of related benzyl hydrazine-1-carbodi-thio-ate are surveyed and compared with those of the title compound.

Crystal structure and Hirshfeld surface analysis of a conformationally unsymmetrical bis-chalcone: (1E,4E)-1,5-bis-(4-bromo-phen-yl)penta-1,4-dien-3-one.

In the title bis-chalcone, C17H12Br2O, the olefinic double bonds are almost coplanar with their attached 4-bromo-phenyl rings [torsion angles = -10.2 (4) and -6.2 (4)°], while the carbonyl double bond is in an s-trans conformation with with respect to one of the C=C bonds and an s-cis conformation with respect to the other [C=C-C=O = 160.7 (3) and -15.2 (4)°, respectively]. The dihedral angle between the 4-bromo-phenyl rings is 51.56 (2)°. In the crystal, mol-ecules are linked into a zigzag chain propagating along [001] by weak C-H⋯π inter-actions. The conformations of related bis-chalcones are surveyed and a Hirshfeld surface analysis is used to investigate and qu-antify the inter-molecular contacts.

Synthesis, characterization and biological evaluation of transition metal complexes derived from N, S bidentate ligands.

Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC) with 2-methoxybenzaldehyde (2MB) and 3-methoxybenzaldehyde (3MB). The ligands were reacted separately with acetates of Cu(II), Ni(II) and Zn(II) yielding 1:2 (metal:ligand) complexes. The metal complexes formed were expected to have a general formula of [M(NS)2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1) and S2M3MBH (2) were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) breast cancer cell lines. Only the Cu(II) complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II) complexes have a strong DNA binding affinity.

4-{(E)-2-[4-(But-3-en-1-yl-oxy)phen-yl]diazen-1-yl}benzoic acid.

The title compound, C(17)H(16)N(2)O(3), has an E conformation about the azobenzene (-N=N-) linkage. The benzene rings are twisted slightly with respect to each other [6.79 (9)°], while the dihedral angle between the plane through the carb-oxy group and the attached benzene ring is 3.2 (2)°. In the crystal, mol-ecules are oriented with the carb-oxy groups head-to-head, forming O-H⋯O hydrogen-bonded inversion dimers. These dimers are connected by C-H⋯O hydrogen-bonds into layers lying parallel to the (013) plane.

1,4-Dibromo-2,5-dibut-oxy-benzene.

The asymmetric unit of the title compound, C(14)H(20)Br(2)O(2), contains one half-mol-ecule located on an inversion centre. The mol-ecule is essentially planar, with a maximum deviation from the best plane of the non-H atoms of 0.054 (2) Šfor the O atoms. The but-oxy group adopts a fully extended all-trans conformation. In the crystal, mol-ecules are connected via C-Br⋯O halogen bonds [Br⋯O = 3.2393 (19) Å] into a two-dimensional corrugated network in the bc plane.

(Bipyridine-κ(2)N,N')chlorido[N-(2-hydroxy-ethyl)-N-isopropyl-dithio-carbamato-κ(2)S,S']zinc(II).

The Zn(II) atom in the title compound, [Zn(C(6)H(12)NOS(2))Cl(C(10)H(8)N(2))], is coordinated by a chelating N-2-hy-droxy-ethyl-N-isopropyl-dithio-carbamate ligand, a 2,2'-bipyridine ligand and a Cl atom. The resulting ClN(2)S(2) donor set defines a distorted square-pyramidal coordination geometry. Helical supra-molecular chains sustained by O-H⋯S hydrogen bonds and propagating along the b axis feature in the crystal packing. A three-dimensional architecture is stabilized by C-H⋯O, C-H⋯S and C-H⋯Cl inter-actions.

2,2'-[2,5-Bis(hex-yloxy)-1,4-phenyl-ene]dithio-phene.

The asymmetric unit of the title compound, C(26)H(34)O(2)S(2), comprises one half-mol-ecule located on an inversion centre. The thio-phene groups are twisted relative to the benzene ring, making a dihedral angle of 5.30 (7)°, and the n-hexyl groups are in a fully extended conformation. In the crystal, there are short C-H⋯π contacts involving the thio-phene groups.

Bis{S-benzyl 3-[(phen-yl)(pyridin-2-yl)methyl-idene]dithio-carbazato}zinc acetonitrile monosolvate.

In the title compound, [Zn(C(20)H(16)N(3)S(2))(2)]·CH(3)CN, two different Schiff base moieties coordinate to the central Zn(II) ion as tridentate N,N',S-chelating ligands, creating a distorted octa-hedral environment [the smallest angle being 73.24 (6)° and the widest angle being 155.73 (7)°], with the two S atoms in cis positions. The dihedral angle between the mean planes of the two coordinating ligands is 83.65 (5)°. The crystal packing is consolidated by weak C-H⋯N hydrogen-bonding inter-actions.

rac-[3-Hydroxy-6,9-dimethyl-6-(4-methylpent-3-en-1-yl)-6a,7,8,9,10,10a-hexahydro-6H-1,9-epoxybenzo[c]chromen-4-yl](phenyl)methanone.

The title compound congestiflorone, C(28)H(32)O(4), which was isolated from the stem bark of Mesua congestiflora, consists of a benzophenone skeleton with two attached pyran rings to which a cyclo-hexane ring and a C6 side chain are bonded. The benzene ring is significantly distorted from planarity (r.m.s. deviation = 0.0007 Å) due to the constraints imposed by junctions with the two pyran rings. The cyclo-hexane ring is in a chair conformation, one pyran ring is in a boat conformation, while the other is a distorted chair. The phenyl and benzene rings make a dihedral angle of 55.85 (9)°. An intra-molecular O-H⋯O hydrogen bond is observed. In the crystal, mol-ecules are linked via C-H⋯O inter-actions.

{S-Benzyl 3-[(6-methyl-pyridin-2-yl-κN)methyl-idene]dithio-carbazato-κ(2)N(3),S}zinc.

The title compound, [Zn(C(15)H(14)N(3)S(2))(2)], contains two chemically equivalent Schiff base anions that are coordinated to the Zn(II) ion as tridentate N,N',S-chelating ligands, creating a distorted octa-hedral environment [the smallest angle being 75.40 (6)° and the widest angle being 162.87 (6)°], with the two S atoms in cis positions. The dihedral angle between the mean planes of the two coordinating ligands is 85.65 (5)°. Weak C-H⋯S hydrogen bonds are also observed.

Bis{S-benzyl 3-[(6-methyl-pyridin-2-yl)methyl-idene]dithio-carbazato}nickel(II).

The asymmetric unit of the title compound, [Ni(C(15)H(14)N(3)S(2))(2)], consists of two independent mol-ecules with similar configurations. Each Ni(2+) cation is coordinated in a cis-mode by two tridentate N,N',S-chelating Schiff base ligands, creating a distorted octa-hedron [the smallest angle being 77.57 (7)° and the widest being 168.97 (7)° for one mol-ecule, and 78.04 (7) and 167.55 (7)° for the second mol-ecule]. The dihedral angle between the mean coordination planes of the two ligands is 86.76 (7)° for one and 89.99 (7)° for the second mol-ecule. π-π inter-actions between neighbouring pyridine rings with plane-to-plane distances of 3.540 (1) and 3.704 (1) Šare observed.

{S-Benzyl 3-[(6-methyl-pyridin-2-yl)-methyl-idene]dithio-carbazato}nickel(II) monohydrate.

The structure of the title compound, [Ni(C(15)H(14)N(3)S(2))(2)]·H(2)O, has one mol-ecule in the asymmetric unit, along with a solvent water mol-ecule. The two different Schiff base moieties coordinate to the central Ni(II) ion as tridentate N,N',S-chelating ligands, creating a six-coordinate distorted octa-hedral environment [the smallest angle being 77.43 (7)° and the widest angle being 169.99 (7)°]. The mean planes of the two ligands are nearly orthogonal to each other with an angle of 89.53 (6)°. The packing of the complex is supported by O-H⋯N and O-H⋯S hydrogen bonding between the solvent water mol-ecule and the uncoordinated N and S atoms of neighbouring ligands.

(N-Ethyl-N-phenyl-dithio-carbamato-κS)triphenyl-tin(IV).

The title compound, [Sn(C(6)H(5))(3)(C(9)H(10)NS(2))], has two independent mol-ecules in the asymmetric unit and each features a tetra-hedrally coordinated Sn(IV) atom as the dithio-carbamate ligand coordinates in a monodentate fashion. As the non-coordinating thione S atom is proximate to the Sn atom [Sn⋯S(thione) = 3.1477 (6) and 2.9970 (5) Šfor the independent mol-ecules], distortions from the ideal geometry are evident [the widest angle being 120.48 (5)°]. The most notable feature of the crystal packing is the formation of C-H⋯π inter-actions that lead to the formation of supra-molecular layers parallel to ([Formula: see text]2[Formula: see text]).

Di-n-butyl-bis-(N-ethyl-N-phenyl-dithio-carbamato-κS)tin(IV).

The title compound, [Sn(C(4)H(9))(2)(C(9)H(10)NS(2))(2)], features a tetra-hedrally coordinated Sn(IV) atom; the dithio-carbamate ligands coordinate in a monodentate fashion, accompanied by two n-butyl chains. The non-coordinating thione S atoms are each proximate to the Sn(IV) atom [3.0136 (7) and 2.9865 (8) Å], giving rise to distortions from the ideal geometry as evident in the wide C-Sn-C bond angle of 139.06 (12) °. In the crystal, C-H⋯S inter-actions lead to the formation of a linear supra-molecular chain along the b axis. The chains are aligned into layers by C-H⋯π inter-actions, and the layers stack along [001]. One of the ethyl groups is statistically disordered over two sets of sites.

3-Amino-5-(piperidin-1-yl)thio-phene-2,4-dicarbonitrile.

In the title compound, C(11)H(12)N(4)S, the thio-phene ring is roughly planar, with a maximum deviation of 0.012 (1) Šfor the S atom, and makes a dihedral angle of 7.89 (8)° with the mean plane of the piperidine ring, which is in a chair conformation. The crystal packing is stabilized by pairs of centrosymmetric inter-molecular N-H⋯N hydrogen bonds, which results in the formation of a step-wise chain parallel to [10[Formula: see text]].

N-(Pyrrolidin-1-ylcarbothio-yl)benzamide.

In the title compound, C(12)H(14)N(2)OS, the pyrrolidine ring adopts an envelope conformation with the C atom at the 3-position as the flap and makes a dihedral angle of 65.80 (9)° with the benzene ring. In the crystal, N-H⋯O hydrogen bonds join c-glide related mol-ecules into chains extended along [001] that are further connected into (100) layers via C-H⋯O inter-actions.

1-[4-(Prop-2-en-1-yl-oxy)benz-yl]-2-[4-(prop-2-en-1-yl-oxy)phen-yl]-1H-benzimidazole.

In the title compound, C26H24N2O2, the benzimidazole ring system is almost planar [maximum displacement = 0.025 (1) Å] and makes dihedral angles of 80.48 (5) and 41.57 (5)° with the benzene rings, which are inclined to one another by 65.33 (6)°. In the crystal, mol-ecules are linked via C-H⋯π and weak π-π inter-actions [centroid-centroid distance = 3.8070 (7) Šand inter-planar distance = 3.6160 (5) Å].

2-Cyclo-hexyl-idene-N-methyl-hydrazine-carbothio-amide.

The title compound C(8)H(15)N(3)S has two mol-ecules in the asymmetric unit in which cis-trans isomerism is exhibited around the N(NH)C=S bonds. The cyclo-hexyl rings in both mol-ecules adopt a chair conformation. In the crystal, N-H⋯S hydrogen bonding produces dimers, which are inter-connected through further N-H⋯S hydrogen bonds, forming chains along the b-axis direction.