Mercury Complexes Research Articles

Mercury(II) halide complex of cis-[( t BuNH)(Se)P(μ-N t Bu)2P(Se)(NH t Bu)

The mercury(II) halide complex [1,3-di-tert-butyl-2,4-bis(tert-butylamino)-1,3,2λ5,4λ5-diazadiphosphetidine-2,4-diselone-κ2 Se,Se′]diiodidomercury(II) N,N-dimethylformamide monosolvate, [HgI2(C16H38N4P2Se2)]·C3H7NO or (1)HgI2, 2, containing cis-[( t BuNH)(Se)P(μ-N t Bu)2P(Se)(NH t Bu)] (1) was synthesized and structurally characterized. The crystal structure of 2 confirms the chelation of chalcogen donors to HgI2 with a natural bite angle of 112.95 (2)°. The coordination geometry around mercury is distorted tetrahedral as indicated by the τ4 geometry index parameter (τ4 = 0.90). In the mercury complex, the exocyclic tert-butylamido substituents are arranged in an (endo, endo) fashion, whereas in the free ligand (1), the exocyclic substituents are arranged in an (exo, endo) pattern. Compound 2 displays non-classical N—H...O hydrogen-bonding interactions with the solvent N,N-dimethylformamide. These interactions may introduce geometrical distortion and deviation from an ideal geometry. An isostructural HgBr2 analogue containing cis-[( t BuNH)(S)P(μ-N t Bu)2P(S)(NH t Bu)] was also synthesized and structurally characterized, CIF data for the compound being presented as supporting information.

Synthetic and theoretical study on novel N-ylidic complexes of mercury as new antibacterial agents

The novel structure of Hg(II) complexes including the pyridinium ylide C5H5NCHC(O)C6H4-m-Br (Y) were synthesized and reported in this study. In the first step, the pyridinium salt C5H5NCH2C(O)C6H4-m-Br (S) was produced by reacting 2,3′-dibromoactophenone and pyridine. then, treatment of S with K2CO3 gave the related pyridinium ylide Y. Finally, the reaction of Y with HgX2 and Hg(NO3)2·H2O leads to the formation of novel binuclear [HgY2][HgX4] (X=Cl (1); X=Br (2); X=I (3)) and polymeric [HgY(NO3)2]n (4) complexes. The structure of complex 2 was also determined by X-ray diffraction analysis. The obtained analyses proved the coordination through the ylidic carbon to metallic center. Additionally, Natural Bond Orbital (NBO), Energy Decomposition Analysis (EDA), and EDA-NOCV studies are also used to investigate the nature of metal–ligand bonding in the complexes. Finally, the antibacterial activity of 1–4 was also examined against Gram positive and negative represented significant levels of inhibitory potency respected to used standards.

On the geometry dependence of the nuclear magnetic resonance chemical shift of mercury in thiolate complexes: A relativistic density functional theory study.

Thiolate containing mercury(II) complexes of the general formula [Hg(SR) ] have been of great interest since the toxicity of mercury was recognized. 199Hg nuclear magnetic resonance spectroscopy (NMR) is a powerful tool for characterization of mercury complexes. In this work, the Hg shielding constants in a series of [Hg(SR) ] complexes are therefore investigated computationally with particular emphasis on their geometry dependence. Geometry optimizations and NMR chemical shift calculations are performed at the density functional theory (DFT) level with both the zeroth-order regular approximation (ZORA) and four-component relativistic methods. The four exchange-correlation (XC) functionals PBE0, PBE, B3LYP, and BLYP are used in combination with either Dyall's Gaussian-type (GTO) or Slater-type orbitals (STOs) basis sets. Comparing ZORA and four-component calculations, one observes that the calculated shielding constants for a given molecular geometry have a constant difference of 1070 ppm. This confirms that ZORA is an acceptable relativistic method to compute NMR chemical shifts. The combinations of four-component/PBE0/v3z and ZORA/PBE0/QZ4P are applied to explore the geometry dependence of the isotropic shielding. For a given coordination number, the distance between mercury and sulfur is the key factor affecting the shielding constant, while changes in bond and dihedral angles and even different side groups have relatively little impact.

A comparative investigation on the surface and physicochemical properties of organobimetallic thiocyanate complexes of Cadmium, Zinc, Mercury and Manganese

Abstract The single crystals of bimetallic thiocyanate ligands, namely manganese cadmium thiocyanate (MCTC), zinc cadmium thiocyanate (ZCTC), manganese mercury thiocyanate dimethylsulphoxide (MMTD), and cadmium mercury thiocyanate dimethylsulphoxide (CMTD), are cultivated through the utilization of slow solvent evaporation and gradual cooling methodologies. Through the utilization of optical microscopic techniques such as field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), and epifluorescence, a state-of-the-art methodology extensively employed in the realms of biochemical, medical, and chemical research, we delve into the examination of growth mechanisms and surface topographies. It is additionally employed in LED, fluorescent, and various other luminous sources. The FESEM analysis of MCTC elucidates the manifestation of an extended dendritic growth pattern, which arises from the oscillation of the Mn and Cd metal ligands when connected by thiocyanate (SCN) bridges. The presence of three notable mounds exhibiting cavities within the multi-component thin film coating (MCTC) has been duly ascertained through the utilization of atomic force microscopy (AFM) imagery. The analysis of the histogram unveiled that the average diameter exhibited an augmentation concomitant with the alteration in the breadth of the distribution throughout the process of growth.

Gold(III), Mercury(II), and Palladium(II) Complexes of a Series of Isomeric Bis(mono- and dialkoxyphenyl)pyridines: Introduction of Gold through Transmetalation and Catalysis.

A series of isomeric bis-2,6-(monoalkoxyphenyl)pyridine and bis-2,6-(dialkoxyphenyl)pyridine ligands were synthesized and characterized. In order to prepare their chlorogold(III) complexes, intermediate chloromercury(II) complexes were first prepared, but unlike observations from previous studies where they were obtained impure and at best in moderate yield, here pure complexes were synthesized, many in rather high yields. Depending on the substitution pattern of the alkoxy chains on the ligands, mono- and/or dimercurated complexes were obtained, characterized by 1H, 13C{1H}, and 199Hg NMR spectroscopy as well as, in several cases, by X-ray crystallography. Factors that may explain this unusual reactivity are discussed. In most cases, transmetalation to the related chlorogold(III) complex proceeded smoothly, although lower yields were obtained when starting from doubly mercurated precursors. Prompted by the propensity of these ligands to mercurate, attempts were made to effect direct auration, but none was successful. However, dimeric, orthometalated complexes of palladium(II) could be prepared and were also amenable to transmetalation to the chlorogold(III) complex, providing for a mercury-free synthesis.

Synthesis and characterizations of Hg (II) Complex of Macrocyclic complexes compounds Tetradecahydrodibenzo hexaazacyclooctadecine with HgX2 (X= Cl, Br) by Hirshfeld analysis and antimicrobial activity

This study examines the synthesis and characterization of a macrocyclic complex molecule having the general formula [M-LX2], where M =Hg (II) with schiff base Tetradecahydrodibenzo hexaazacyclooctadecine ligands. Resulted from the interaction between mercury and the diethyl triamine and benzene- 1, 2 diol in an ethanolic solution. Schiff base and its novel mercury (II) Complexes were studied vibrational in the solid state using spectral, 1H-NMR, IR, UV, and antimicrobial activity approaches. We were able to establish the coordination mode of the metal in complexes by comparing the changes in the ligands' and complexes' FT-IR and UV-Visible spectra.
 Keywords: MERCURY (II), Schiff bases, IR, 1H-NMR, PXRD Spectroscopy.

Exploration of novel phenyl mercury tetrazole‐thione complexes: Characterization and investigating the impact of diamine ligands on enhanced hydrogen storage

AbstractTen mixed‐ligand phenyl mercury(II) complexes containing 1‐methyl‐1H‐tetrazole‐5‐thiol (HmtzS) (1) and phosphine or amine ligands. These complexes fall into two groups: [PhHg(mtzS){Ph2P(CH2)PPh2}]2 (2) and [PhHg(mtzS){Ph2P(CH2)nPPh2}] (3‐6), where n varies, and [PhHg(mtzS)(diamine)] (8‐10), with diamine choices being 2,2′‐bipyridyl (Bipy, 8), 1,10‐phenathroline (Phen, 9), or ethylenediamine (en, 10). These complexes were synthesized with moderate to high yields and characterized using various techniques. Characterization data revealed that the mtzS− ligand coordinates as a monodentate ligand through the thiolate sulfur atom in all complexes, adopting a tetrahedral geometry around the Hg(II) center. Furthermore, complexes [PhHg(mtzS)] (1) and its diamine derivatives (8‐10) were assessed for hydrogen storage at 77 K using the VTI method. Results demonstrated that the incorporation of diamines improves hydrogen storage capacity at low pressure. The precursor stored (1) 2.3 wt.% at 80 bar, while the other complexes showed storage capacities ranging from 2.9 to 3.86 wt.% at pressures of 45‐60 bar. Thermodynamic properties of the [PhHg(mtzS)(Bipy)] complex was calculated at three different temperatures. The results prove that the entropy was equal to 0.50543599 J/mol H2. K while the enthalpy equal to 0.0942638 KJ/(mol H2).

From a mercury(II) bis(yldiide) complex to actinide yldiides.

The bis(yldiide) mercury complex, (L-Hg-L) [L = C(PPh3)P(S)Ph2], is prepared from the corresponding potassium yldiide and used to access the first substituted yldiide actinide complexes [(C5Me5)2An(L)(Cl)] (An = U, Th) via salt metathesis. Compared to previously reported phosphinocarbene complexes, the complexes exhibit long actinide-carbon distances, which can be explained by the strong polarization of the π-electron density toward carbon.

Theoretical Studies of Xanthates in Heavy Metal Complexation: Understanding the Structural, Thermochemical, and Electronic Aspects

Heavy metals have been widely discussed as a significant cause of environmental disasters in recent decades. One of the main focuses has been exploring agents and mechanisms capable of removing these metals from nature. Under this perspective, xanthates have been studied as sequestering agents of these metals in aqueous environments. In this theoretical study, complexes of cadmium(II) and mercury(II), with different coordination modes and geometric isomers of the xanthate ligands (n-propyl, n-butyl, and n-pentyl xanthates), were evaluated using density functional theory. To verify the versatility of coordination modes of the xanthates, monodentate and bidentate structures were optimized. For these compounds, structural, thermochemical, and electronic parameters were studied. The thermochemical results showed that all complexes are formed through exothermic and spontaneous processes. Electronic analysis showed that the mercury(II) complexes have a higher covalent character of the Hg-S bond, in contrast with the cadmium(II) complexes, which exhibited a higher ionic character of the Cd-S bond. Through the analysis of the natural bond orbitals, the Lewis acid-base nature of these complexes was confirmed and corroborated by the softness calculations, with the participation of the p orbitals of the sulfur and s orbitals of the metal centers.

A strategy for obtaining isostructurality despite structural diversity in coordination compounds

To report a methodology for the construction of supramolecular architectures to obtain isostructural compounds through the diversion of the structures, a series of mercury complexes containing N-(3-halophenyl)-2-pyridinecarboxamide ligands, have been synthesized for a systematic.

Synthesis and Characterization of Mercury Complex Derived from Trimesic Acid

The effects of mercury complexes on human body and cells vary depending on the extent of exposure and their pharmacological form. Objectives: To characterize mercury complex and then investigate the effects on cellular interaction via cell death. Methods: The synthesis of the mercury complex was carried out, and its characterization was done by FTIR, elemental percentage and powder X-ray diffraction (PXRD). The complex was analyzed through atomic force microscopy (AFM) and by microscopy imaging its surface morphology and cellular interaction were also studied. Results: The presence of the mercury-complex results in cell death in concentration and time dependent manner. Conclusions: The synthesized mercury-complex has the ability to harm cells.

Selective sensing of sulphide ion by a simple mercury (II) complex of an amino-substituted terpyridine in aqueous solution

A novel mercury complex HgCl2L of 4′-(4-N,N´-dimethylaminophenyl)-2,2´:6′,2´´-terpyridine ligand L has been synthesized and characterised using 1H NMR, HRMS, FT-IR spectroscopy and CHN analysis. The crystal structure of HgCl2L exhibits distorted square pyramidal geometry. Further, the complex HgCl2L is utilised for selectively detecting sulphide (S2−) anion with other competitive anions in aqueous acetonitrile (4:1 v/v) medium. UV–visible absorption spectral studies and colorimetric approach confirmed the selectivity of the complex towards S2- and the limit of detection has been determined to be 1.01 μM.

Synthesis, characterization, and theoretical studies on ylidic complexes of mercury(II) as antioxidant agents

Herein we describe the synthesis of a library of new mercury complexes, including some dimers and polymeric species. Initially, a phosphonium salt, [PPh3CH2C(O)C6H4–m-OCH3]Br (S), was synthesized from triphenylphosphine (PPh3) and BrCH2C(O)C6H4-m-OCH3 in acetone. We then reacted this phosphonium salt with an appropriate base to acquire a new phosphorus ylide monodentate, PPh3=C(H)C(O)C6H4-m-OCH3 (Y). Finally, we treated the synthesized ligand with mercury halides in dry CH3OH to form C-coordinated complexes of the form [HgX(PPh3C(H)C(O)C6H4-m-OCH3) (μ-X)]2 [X = Cl (1), Br (2), I (3)], [(PPh3=C(H)C(O)C6H4-m-OCH3)Hg(NO3)2]n (4). We characterized these compounds using CHN analysis, FT-IR, NMR (1H, 13C and 31P) and density functional theory. We elucidated the structure of 2 by single-crystal X-ray diffraction. The results establish that 1, 2 and 3 have dimeric structures, while a polymeric structure is suggested for 4. The antioxidant activity of all compounds in DMSO was assessed using a DPPH free radical scavenging method. Also, the nature of metal-ligand (C→Hg) bonding in 1, 2 and 3 have been investigated using natural bond orbital (NBO) and energy-decomposition analyses (EDA).

E- or Z-Isomers Arising from the Geometries of Ligands in the Mercury Complex of 2-(Anthracen-9-ylmethylene)-N-phenylhydrazine Carbothioamide.

An anionic mercury(II) complex of 2-(anthracen-9-ylmethylene)-N-phenylhydrazine carbothioamide (HATU) and two isomers of a neutral mercury(II) complex of the anion of the same ligand (ATU) were reported. The anionic complex [Hg(HATU)2Cl2]·CH2Cl2 had a monodentate HATU ligand (a neutral form of the ligand) and chloride ligands. The two conformational isomers were of the neutral mercury(II) complex Hg(ATU)2·2DMF. The two isomers were from the E or Z geometry of the ligands across the conjugated C=N-N=C-N scaffold of the coordinated ligand. The two isomers of the complex were independently prepared and characterized. The spectroscopic properties of the isomers in solution were studied by 1H NMR as well as fluorescence spectroscopy. Facile conversion of the E-isomer to the Z-isomer in solution was observed. Density functional theory (DFT) calculations revealed that the Z-isomer of the complex was stable compared to the E-isomer by an energy of 14.35 kJ/mol; whereas, E isomer of the ligand was more stable than Z isomer by 8.37 KJ/mol. The activation barrier for the conversion of the E-isomer to the Z-isomer of the ligand was 167.37 kJ/mol. The role of the mercury ion in the conversion of the E-form to the Z-form was discussed. The mercury complex [Hg(HATU)2Cl2]·CH2Cl2 had the E-form of the ligand. Distinct photophysical features of these mercury complexes were presented.

Formation of an Unusual Pseudo-Square Planar-Induced Mercury(II) Dimeric Complex

Due to the different crystallization methods, two Hg(II) complexes of a 19-membered NO2S2-macrocycle (L) and its oxidized ligand (HLox), exhibiting different stoichiometries, were prepared. First, mercury(II) iodide reacts with L to afford a dinuclear metallacycle complex [Hg2(L)2I4] (1) in which the mercury(II) exists outside the macrocyclic cavity. Meanwhile, the slow diffusion reaction gave an unusual pseudo-square planar-induced mercury(II) complex, which shows three separated parts with the formula [Hg2(HLox)I5]2[HgI2] (2). There are two complex cation units that are exo-coordinated, along with one unit consisting of a metal cluster anion. Surprisingly, L was oxidized in the disulfoxidized form (HLox) in this condition. NMR titration was used to monitor both the structural and binding characteristics of the complex formed between L and mercury(II) iodide in a solution.

Neurobehavioral effects of the exposure to mercury vapor and methylmercury during postnatal period on mice.

In this study, we investigated the neurobehavioral alterations and modifications of gene expression in the brains of female mice exposed to low-level mercury vapor and/or methylmercury during postnatal development. The mice were exposed to low-level mercury vapor at a mean concentration of 0.094mg/m3 and supplied with tap water containing 5 ppm methylmercury from postnatal day 11 to 12 weeks of age. Behavioral analyses were performed at 17 weeks of age. Total locomotor activity in the open field test and the retention trial performance in the passive avoidance test were significantly reduced in the combined exposure group compared with those in the control group. The differences in locomotor activity and performance in the retention trial at 17 weeks were no longer detected at 45 weeks. These results suggest that the effect of aging on the behavioral abnormalities resulting from postnatal exposure to mercury complexes are not significant. In the microarray analysis of brains in the combined exposure group, the gene expression levels of Ano2 and Sgk1 were decreased. Real-time RT-PCR analysis confirmed these changes caused by combined mercury exposure, showing significant downregulation of Ano2 and Sgk1 in the cerebrum. These genes play key roles in the brain as a calcium-activated chloride channel and as a kinase that responds to cellular stress, respectively. Our findings provide insight into the neurobehavioral changes caused by combined mercury exposure.

Phosphine and Selenoether peri-Substituted Acenaphthenes and Their Transition-Metal Complexes: Structural and NMR Investigations.

A series of peri-substituted acenaphthene-based phosphine selenoether bidentate ligands Acenap(iPr2P)(SeAr) (L1-L4, Acenap = acenaphthene-5,6-diyl, Ar = Ph, mesityl, 2,4,6-trisopropylphenyl and supermesityl) were prepared. The rigid acenaphthene framework induces a forced overlap of the phosphine and selenoether lone pairs, resulting in a large magnitude of through-space 4JPSe coupling, ranging from 452 to 545 Hz. These rigid ligands L1-L4 were used to prepare a series of selected late d-block metals, mercury, and borane complexes, which were characterized, including by multinuclear NMR and single-crystal X-ray diffraction. The Lewis acidic motifs (BH3, Mo(CO)4, Ag+, PdCl2, PtCl2, and HgCl2) bridge the two donor atoms (P and Se) in all but one case in the solid-state structures. Where the bridging motif contained NMR-active nuclei (11B, 107Ag, 109Ag, 195Pt, and 199Hg), JPM and JSeM couplings are observed directly, in addition to the altered JPSe in the respective NMR spectra. The solution NMR data are correlated with single-crystal diffraction data, and in the case of mercury(II) complexes, they are also correlated with the solid-state NMR data and coupling deformation density calculations. The latter indicate that the through-space interaction dominates in free L1, while in the L1HgCl2 complex, the main coupling pathway is via the metal atom and not through the carbon framework of the acenaphthene ring system.

Arsenic(II) Complexes of Acetic Acid (3-nitrobenzyli- Dene)–hydrazide(schiff Bases Ligands):synthesis and Spectral Characterization

The synthesis and characterization of arsenic(II) complexes with Schiff base ligands, [AsL)]Cl2 (L=Acetic acid (3-nitrobenzylidene) – hydrazide are described. Vibrational study in the solid state of hydrazide derivatives and its new mercury(II) complexes was performed by IR spectroscopy, UV spectral techniques. The changes observed between the FT-IR and UV-Vis spectra of the ligands and of the complexes allowed us to established the coordination mode of the meal in complexes. The results suggest that the Schiff bases coordinate as univalent anions with their bidentate N,O donors derived from the carbonyl and azomethine nitrogen.

Mercury selective hydrogelation of a pyridinyl substituted terpyridine ligand

We report the addition of aqueous solution of different divalent transition metal ions M2+ (M = Mn, Fe, Co, Ni, Cu, Zn, Cd, Hg) to a dilute acidic solution of 4′-(pyridin-2-yl)-2,2′:6′,2″-terpyridine (L). An irreversible, translucent, and thixotropic hydrogel was selectively produced in the case of Hg(II). FESEM and HR-TEM images of Hg(II)-hydrogel showed non-uniform, fibrous, and cross-linked gel morphology. Further, the hydrogel was treated with sodium salts of different anions (F−, I−, Br−, Cl−, SO42−, NO3−, HCO3−, SO32−) in water. The iodide ion showed unusual behavior by forming a yellow precipitate of the hydrogel with a plate-like structure, as observed from FESEM images. DFT study has also been conducted to understand the aggregation behavior in Hg(II) based hydrogel. We also synthesized the mercury complex HgCl2L and characterized it by 1H NMR, elemental analysis, and mass spectrometry.

Design, synthesis, characterization, spectral, chemical analysis, biological evaluation, and molecular docking studies of novel fatty Schiff base ligands and their nickel and mercury complexes

A novel two Fatty Schiff bases ligands of (N-(4-(dimethyl amino) benzylidene Dodecane, heptadecane) hydrazide and N-(4-(dimethyl amino) benzylidene) dodecane, heptadecan hydrazides and their complexes with Hg and Ni were synthesized and distinguish by1HNMR, FT-IR, spectroscopy, elemental analysis, X-ray Diffractions, thermal gravimetric analysis, and magnetic moments. In-vitro strains have been used to study their antibacterial properties. The ligands and their metal complexes have been evaluated physiologically by various bacterial and fungal strains. In the comparison of free ligands with their complexes. The latter were a more potent antibacterial agent and were more efficient against gram-positive bacteria than gram-negative bacteria. Additionally, investigations using molecular docking have been carried out to assess the ideal binding location and its inhibitory effect.