Structural characterization of dichloridobis(N,N’-dimethylthiourea-S)cadmium(II)

Modulation of Cadmium Tolerance in Rice: Insight into Vanillic Acid-Induced Upregulation of Antioxidant Defense and Glyoxalase Systems

Cadmium (Cd) is a toxic heavy metal that enters the human food chain from the soil via plants. Increased Cd uptake and translocation in plants alters metabolism andreduces crop production. Maintaining crop yield therefore requires both soil remediation andenhanced plant tolerance to Cd. In this study, we investigated the effects of vanillic acid (VA) on Cd accumulation and Cd stress tolerance in rice (Oryza sativa L. cv. BRRI dhan54). Thirteen-day-old rice seedlings treated with CdCl₂ (1.0 and 2.0 mM) for 72 h showed reduced growth, biomass accumulation, and water and photosynthetic pigment contents, as well as increased signs of oxidative stress (elevated levels of malondialdehyde, hydrogen peroxide, methylglyoxal, and lipoxygenase) and downregulated antioxidant and glyoxalase systems. Cadmium-induced changes in leaf relative turgidity, photosynthetic pigment content, ascorbate pool size, and glutathione content were suppressed by VA under both mild and severe Cd toxicity stress. The supplementation of VA under Cd stress conditions also increased antioxidant and glyoxylase enzyme activity. Vanillic acid also increased phytochelatin content and the biological accumulation factor, biological accumulation co-efficient, and Cd translocation factor. Vanillic acid, therefore appears to enhance Cd stress tolerance by increasing metal chelation and sequestration, by upregulating antioxidant defense and glyoxalase systems, and by facilitating nutrient homeostasis.

Crystal structure of di-chlorido-bis-(1,3-diazinane-2-thione-κS)cadmium

In the structure of the title compound, [CdCl2(C4H8N2S)2], the Cd(II) atom is coordinated by two chloride ions and two 1,3-diazinane-2-thione (Diaz) mol-ecules through their S atoms. The geometry around the Cd(II) atom is distorted tetra-hedral, with bond angles in the range 101.55 (7)-117.91 (8)°. The CH2 groups of one Diaz ligand are disordered over two sets of sites with an occupancy ratio of 0.711 (12):0.289 (12). The mol-ecular structure is stabilized by intra-molecular N-H⋯Cl hydrogen-bonding inter-actions, generating a butterfly syn conformation. Inter-molecular N-H⋯Cl and N-H⋯S inter-actions lead to the formation of a three-dimensional network structure. The structure has been determined from a crystal twinned by nonmerohedry, by a 180° rotation around the reciprocal c axis. The twin ratio refined to 0.8866 (6):0.1134 (6).

Crystal structure of di-chlorido-bis-(N,N'-di-methyl-thio-urea-κS)mercury(II)

The mol-ecular structure of the title compound, [HgCl2(C3H8N2S)2], has point group symmetry 2, with the twofold rotation axis passing through the Hg(II) atom. The latter is coordinated by two Cl atoms and two N,N'-di-methyl-thio-urea (Dmtu) ligands through their S atoms, defining a distorted tetra-hedral coordination sphere with bond angles in the range 102.47 (4)-118.32 (4)°. Intra- and inter-molecular hydrogen bonds of the type N-H⋯Cl with S(6) and R 2 (2)(12) ring motifs are present. The inter-molecular contacts make up polymeric chains extending parallel to [101].

Isab A, Ahmad S. Dicyanidobis(thiourea-κS)cadmium(II) monohydrate

In the title compound, [Cd(CN)₂(CH₄N₂S)₂]·H₂O, the Cd atom lies on a twofold rotation axis and is bonded to two S atoms of thio­urea and two C atoms of the cyanide anions in a distorted tetra­hedral environment. The crystal structure is stabilized by N—H⋯N(CN), N—H⋯O, O—H⋯N and N—H⋯S hydrogen bonds.