SYNTHESIS, STRUCTURE OF THE NI (II) COMPLEX OF 4-HYDROXYBENZOIC ACID

Аннотация

4-Hydroxybenzoic acid has antibacterial (against Gram+ve and Gram-ve bacteria), antimicrobial, antimutagenic, blood clot prevention and estrogenic activity. In addition, it is used as a "trap" to study the formation of hydroxyl radicals during cerebral ischemia and reperfusion (restoration of blood flow) and is widely used as a preservative in drugs, cosmetics, pharmaceuticals, food and beverages [1, 2528 p.]. It was found that p-hydroxybenzoic acid increases the resistance of winter wheat (Tritisum aestivum) to external abiotic stress under drought conditions [1, 2528 p.]. Its coordination compounds have been studied for their stimulating properties [2, 588p.]. Aim of the work Obtaining of the structure a complex combination of pHBA with nickel, studying its composition and structure. “SYNTHESIS, STRUCTURE OF THE NI (II) COMPLEX OF 4-HYDROXYBENZOIC ACID” P age 1 | 6 KEYWORDS: Ni complex, single crystal X-ray diffraction, crystal structure, coordination compound. INTRODUCTION After the ligand solution was added dropwise to the Ni(II) salt solution, the color of the 4-Hydroxybenzoic acid with empirical formula obtained solution gradually turned to light C7H6O3, molecular mass 138.1, melting point green. The resulting solution was stirred on a 216.2ºС (see Figure 1) from carrot (Daucus magnetic stirrer at room temperature for 1 carota), oil palm (Elaeis guineensis), grape hour. The solution was then left in a beaker (Vitis vinifera), yellow leaf tree with small holes for evaporation at room (Xanthophyllum rubescens), obtained temperature. After about 3 weeks, single naturally or synthetically from peroba tree crystals of the complex compound appeared. (Paratecoma peroba), southern catalpa tree To determine the crystal structure, data were (Catalpa bognonioides), Cuban royal palm analyzed on an Oxford diffraction Xcalibur-R (Roystonea regia) [4, 109p.]. Additionally, 4- SSD diffractometer (CuKa-radiation, hydroxybenzoic acid is also found naturally in λ=1.54184 Å, ω-scanning mode, graphite plants such as Vitex agnus-castus and monochromator) at 293 K. The structure was Hypercium perforatum. It can also be found in solved by the direct method using the SHELX- coconut fruit and methods of its extraction 2014 software package. All non-hydrogen have also been developed [5, 379p.]. Among atoms were anisotropically refined. Hydrogen Azerbaijani scientists, Rasulov et al. It was atoms were placed in calculated locations and announced that p-hydroxybenzoic acid was constrained by isotropic thermal parameters. isolated from the extract of Centaurea Drawings of the molecule were created using polypodiifolia plant [6, 495b.]. the MERCURY program [3]. Obtained results: The crystal has an orthorhombic structure and space group Pca2/1. a=7.5845(3), b=11.2963(4), c= 23.9669(7), a, b, g = 90°, and the crystal size is V=2053.41. The complex has a total of 5 intermolecular and 1 internal hydrogen bonds. But the polyhedron was found to be a Figure-1 pHBA distorted octahedron. When the valence bond lengths were studied in relation to its spatial The pKa value is equal to 4.58 [7, 17 p.], which structure, the values obtained together with shows acidic property. It undergoes reactions the angles confirmed the distorted structure. typical of organic acids [8, 1255 p.]. RESULTS AND DISCUSSION