Zinc Complexes Research Articles

Hydrogenolysis of Cationic Half-Sandwich Zinc Complexes Containing a Chelating Amine: Facile Cleavage of Zinc-Carbon Bond by Dihydrogen To Give Zinc Hydride Cations.

Cationic half-sandwich zinc complexes containing chelating amines [Cp*Zn(Ln)][BAr4F] (2a, Cp* = η3-C5Me5, Ln = N,N,N',N'-tetramethylethylenediamine, TMEDA; 2b, Ln = N,N,N',N'-tetraethylethylenediamine, TEEDA; 2c, Cp* = η1-C5Me5, Ln = N,N,N',N'',N''-pentamethyl-diethylenetriamine, PMDTA; Ar4F = (3,5-(CF3)2C6H3)4) reacted with dihydrogen (ca. 2 bar) in THF at 80 °C to give molecular zinc hydride cations [(Ln)ZnH(thf)m][BAr4F] (3a,b, m = 1; 3c, m = 0) previously reported along with Cp*H. Pseudo first-order kinetics with respect to the concentration of 2b suggests heterolytic cleavage of dihydrogen by the Zn-Cp* bond, reminiscent of σ-bond metathesis. Hydrogenolysis of the zinc cation 2b in the presence of benzophenone gave the zinc alkoxide [(TEEDA)Zn(OCHPh2)(thf)][BAr4F] (5b). Cation 2b was shown to catalytically hydrogenate N-benzylideneaniline. The PMDTA complex 2c underwent C-H bond activation in acetonitrile to give a dinuclear μ-κC,κN-cyanomethyl zinc complex [(PMDTA)Zn(CH2CN)]2[BAr4F]2 (6c).

Synthesis, structural characterization of phenoxo-bridged zinc(II) complexes and their binding interaction with the spike protein of SARS-CoV-2

Synthesis, structural characterization of phenoxo-bridged zinc(II) complexes and their binding interaction with the spike protein of SARS-CoV-2

Efficacy and Mechanism of the Action of Zinc Complex Nitrilo-tris-Methylenephosphonic Acid As an Inhibitor of Corrosion in Low-Carbon Steel in Neutral Bromide- and Iodide-Containing Aqueous Media

Efficacy and Mechanism of the Action of Zinc Complex Nitrilo-tris-Methylenephosphonic Acid As an Inhibitor of Corrosion in Low-Carbon Steel in Neutral Bromide- and Iodide-Containing Aqueous Media

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.

Enhancing CO2 Capture via Metal-Ligand Cooperativity: Tuning Ligand Basicity and Zn(II) Lewis Acidity.

A series of thiosemicarbazonato-hydrazinatopyridine zinc(II) complexes were evaluated as direct air CO2 capture agents. The complexes sequester CO2 in a methanol solution as a metal-coordinated methylcarbonate. The reaction is reversible upon sparging of solutions with an inert gas (N2 or Ar). The capture process involves metal-ligand cooperativity with the noncoordinating nitrogen of the hydrazinatopyridine functional group serving as a Brønsted-Lowry base and the zinc acting as a Lewis acid. In this study, the pendent amine of the thiosemicarbazonato group was varied to include 4-phenyl (ZnL5), 4-(trifluoromethyl)phenyl (ZnL6), 4-cyanophenyl (ZnL7), 4-tolyl (ZnL8), and 4-naphthyl (ZnL9). Hyperconjugation between the pendent group and the ligand core resulted in modulation of the metal ion acidity, as quantified by ligand exchange equilibrium constants (K3 = 193-511) and ligand basicity (pKa,MeOH = 11.09-11.94). Variations in electronic structure that decreased ligand basicity were more than offset by increases in Lewis acidity. The equilibrium constant (K1) for CO2 capture varied from 46300 to 73700. Overall, the value of K1 was directly related to the relative Lewis acidity of the complexes (K3). Notably, there was an overall inverse relationship between K1 and the ligand basicity. The results provide insights into ligand design to further improve CO2 capture.

Self-healing glassy hybrids based on imidazole-functionalized silica nanoparticles with zinc complexes using dynamic and reversible cross-linking

Self-healing glass materials can potentially overcome the inherent limitations of glass, such as brittleness and difficulties in repairing broken sections while maintaining its critical properties. This paper reports a structural design and synthetic strategy for preparing glassy self-healing hybrids with high silica contents. The developed hybrids exhibited excellent self-healing properties based on dynamic and reversible crosslinking owing to the high density of zinc/imidazole units on the silica surface. First, core–shell silica nanoparticles with small multifunctional imidazole/butyl units (diameter: approximately10 nm) and good processability (homogeneous colloidal dispersions in common organic solvents) were synthesized. Afterwards, imidazole-functionalized silica nanoparticles were fabricated using Zn species to obtain self-healing hybrids with high silica contents (>60 wt%). These nanoparticles served as multifunctional and reversible crosslinking sites that dissipated energy, resulting in excellent mechanical, thermal, and healing characteristics. The obtained zinc/imidazole-based silica hybrids remain solid with high storage elasticity in the temperature range of 25–160 °C and high thermal stability corresponding to a 5 wt% weight loss above 280 °C, which were critical for self-healing glass applications. They also exhibited a moderate Young’s modulus of 330 MPa and a self-healing recovery efficiency of 87%. The findings of this study provide new insights into the roles of reversible interactions (metal/ligand exchange reactions) at particle–particle interfaces and high surface functionalities that serve as non-covalent crosslinking points. The prepared hybrids with high silica contents remain solid over a wide temperature range, which can open new avenues for self-healing glass materials.

Copper(II), Nickel(II) and Zinc(II) Complexes of Peptide Fragments of Tau Protein.

Copper(II), nickel(II) and zinc(II) complexes of various peptide fragments of tau protein were studied by potentiometric and spectroscopic techniques. All peptides contained one histidyl residue and represented the sequences of tau(91-97) (Ac-AQPHTEI-NH2), tau(385-390) (Ac-KTDHGA-NH2) and tau(404-409) (Ac-SPRHLS-NH2). Imidazole-N donors of histidine were the primary metal binding sites for all peptides and all metal ions, but in the case of copper(II) and nickel(II), the deprotonated amide groups were also involved in metal binding by increasing pH. The most stable complexes were formed with copper(II) ions, but the presence of prolyl residues resulted in significant changes in the thermodynamic stability and speciation of the systems. It was also demonstrated that nickel(II) and especially zinc(II) complexes have relatively low thermodynamic stability with these peptides. The copper(II)-catalyzed oxidation of the peptides was also studied. In the presence of H2O2, the fragmentation of peptides was detected in all cases. In the simultaneous presence of H2O2 and ascorbic acid, the fragmentation of the peptide is less preferred, and the formation of 2-oxo-histidine also occurs.

Exploring the spectral properties and potential applications of dimethylamine-modified porphyrin and chlorin dyes

The synthesis, structural characterization, and optical properties of new free-base and metalated dimethylamine-based porphyrin (1, 1a) and chlorin (2, 2a) derivatives are presented. The synthetic approach is based on the peripheral substitution of the para-fluor atoms of the commercially available 5,10,15,20-tetrakis(pentafluorophenyl)-21H,23H-porphyrin (H2TPPF20) by dimethylamine (H2Por 1), following the preparation of the analogous chlorin dye (H2Chl 2) using N-methylglycine and p-formaldehyde. Both compounds were then metalated with zinc acetate to perform the corresponding ZnPor 1a and ZnChl 2a dyes. Several photophysical parameters were determined, including absorption and emission features at 298 K (e.g., molar absorptivity coefficients, λ absorption maxima of Soret and/or Q bands, λemission maxima, and ratio of long- to short-wavelength emission intensity), fluorescence quantum yield (ФF), stability (under dark conditions), and photostability (under white light exposure at irradiance of 50 mW.cm−2). The photophysical results were determined and compared for the type of meso-substituted scaffold selected – A4-type – of free-base (1, 2) and zinc(II) complex (1a, 2a). The four compounds exhibit high dark stability in DMF (absorption reduction intensity < 3 %). The Pors 1 and 1a have also high photostability (absorption reduction intensity < 1.5 %), but H2Chl 2 and ZnChl 2a present a considerable absorption reduction, 14.3 % and 22.3 %, respectively. The ФF of the ZnPor 1a (ФF = 0.02) and H2Por 1 (ФF = 0.02) are lower than those of ZnChl 2a (ФF = 0.06) and H2Chl 2 (ФF = 0.09). The developed compounds present potential applications in nonlinear optics, biomarkers, and/or solar cells.

Zinc N,N-bis(2-picolyl)amine Chelates Show Substitution-Dependent Cleavage of Phosphodiesters in Models as Well as of PNAzyme-RNA Bulges.

PNAzymes are a group of artificial enzymes which show promising results in selective and efficient cleavage of RNA targets. In the present study, we introduce a series of metal chelating groups based on N,N-bis(2-picolyl) groups (parent, 6-methyl and 6-amino substituted) as the active sites of novel PNAzymes. An improved synthetic route for the 6-amino analogues is described. The catalytic activity of the chelating groups for cleaving phosphodiesters were assessed with the model substrate 2-hydroxypropyl p-nitrophenyl phosphate (HPNPP), confirming that the zinc complexes have the reactivity order of parent < 2-methyl < 2-amino. The three ligands were conjugated to a PNA oligomer to form three PNAzymes which showed the same order of reactivity and some sensitivity to the size of the RNA bulge designed into the catalyst-substrate complex. This work demonstrates that the kinetic activity observed for the model substrate HPNPP could be translated onto the PNAzymes, but that more reactive Zn complexes are required for such PNAzymes to be viable therapeutic agents.

Spectroscopic, biological activity, molecular docking and hydrogen storage studies of tetrazole-thione complexes

Six nano-tetrazole-thione complexes of the type [M(MmtzS)2] (MII = Ni (1); Zn(4); Cd (5) and Hg (6)} and [M2(MmtzS)4] (MII = Pd (2) and Pt (3)} were synthesized by treating by the reaction of one equivalent mole of inorganic salts {NiCl2·6H2O; Na2PdCl4; K2PtCl4; ZnCl2; CdCl2 and HgCl2} with two equivalent moles of 1-methyl-1,2,3,4-tetrazole-5-thiol (HMmtzS). The synthesized compounds were obtained through investigation by several physicochemical and spectroscopic techniques. XRD and SEM investigations indicate the crystalline and morphological structural studies of the complexes. Additionally, the MmtzSH ligand and their complexes were tested as antimicrobial agents against four pathogenic bacteria species (Escherichia coli, Klebsiella pneumonia, staphylococcus epidermidis, and Staphylococcus aureus), the results showed that the Ni(II) complex displayed the uppermost activity with the region inhibition within 19 mm(activity index = 72%) to 27 mm (activity index= 96 %) compared to the standard antibacterial drug and other complexes. The cytotoxic effect study was applied to colon carcinoma (CaCo2), and hepatoblastoma (HepG2) cell lines, using the MMT method for complexes (1–4). The Ni(II) complex has the highest activity among all tested compounds. In addition, the complexes 4–6 were chosen for hydrogen storage ability. The findings demonstrate the hydrogen-storing capacity of all tested complexes, with the zinc complex demonstrating the highest capacity at 40 bar and 173 K with 0.99 wt.%.

Synthesis, Spectroscopy and Biological Activity Study of Some New Complexes with Schiff Base Derived From Malonic Acid Dihydrazide with 2-pyridine Crboxaldehyde

تم تحضير ثلاث معقدات جديدة Ni (II)و Cu (II) و Zn (II) باستخدام الليكند المحضر الجديد من تفاعل حامض مالونيك ثنائي هيدرازايد مع 2-بيريدين كربوكسالديهايد. حيث شخصت المعقدات لمحضرة وكذلك الليكند باستخدام تقنيات مختلفة مثل FT-IR و UV-Vis و Mass و 1H-NMR و 13C-NMR وتحليل العناصر CHN و تقدير محتوى الكلور والموصلية المولارية والحساسية المغناطيسية والامتصاص الذري لتشخيص هذه المركبات. لكل معقد محضر جديد من النيكل والنحاس والزنك ، كشفت نتائج التشخيص عن معقدات ذات شكل هندسي ثماني السطوح سداسي التناسق. تمت دراسة تأثير المواد المحضرة على الفعالية البيولوجية لاثنين من البكتريا موجبة الغرام Staphylococcus aureus و Bacillus subtitles واثنين من البكتيريا سالبة الجرام Escherichia coli و Pseudomonas aeruginosa ، بالإضافة إلى candida fungusاثبتت جميع المركبات المحضرة قابلية تثبيطيه جيدة باستثناء معقد النيكل، الذي فشل في إحداث أي تأثيرات مثبطة فعالة ضد pseudomonas.

Force/Acid-Activated and Radical-Regulated photochromic luminescence in a binuclear Zero-Dimensional complex for multi-level anti-counterfeiting

Traditional static optical anti-counterfeiting technology can only output a single emission signal, which is easy to replicate and difficult to meet the needs in current high-tech fields. Multi-level stimuli-responsive luminescent materials with internal logical relationship can improve the degree of anti-counterfeiting and resist against the flood of counterfeiting. In this work, we propose to use force and acid dual stimuli to restrict the dissipation path of photogenerated free radicals, which further lead to the radical-actuated photochromic luminescence (PCL) performance. Based on this strategy, a zero-dimensional (0D) dinuclear zinc complex Zn2(9-AC)4(IM)2 (1) with blue luminescent properties (450 nm) was designed and synthesized. The interaction between 9-AC and IM (as 9-AC/IM exciplex) can be cut off by force-induced rearrangement of structural units in the spatial dimensions or acid-induced protonation of 9-AC, achieving the luminescent transformation from 9-AC/IM exciplex (447 nm) to 9-AC/9-AC excimer (480 nm) or 9-HAC (485 nm). At the same time, the PCL performance was activated and the emission intensity quenching rate increased from 4.77 % to 93.86 % or 44.93 % under UV light irradiation, respectively. The solid-state ultraviolet–visible absorption spectra, electron paramagnetic resonance spectra and theoretical calculation confirmed that the activation of PCL performance is due to the fact that the 9-AC• radicals are more difficult to dissipate upon force- or acid-induced stimuli. Combining mechanochromic luminescence (MCL) and PCL, a dynamic anti-counterfeiting quick response (QR) code with multi-level and fast-responsive logic sequence have been designed, which are promising for the application in time-resolved information encryption. This work provides an effective strategy to construct multi-level stimuli-responsive luminescence as novel anti-counterfeiting materials by changing the photogenerated free radical dissipation pathway to activate PCL properties.

In vitro and in vivo antiproliferative activity on lung cancer of two acylhydrazone based zinc(II) complexes

Two acylhydrazone based zinc(II) complexes [Zn(HL)2Cl2(CH3OH)2] (Zn1) and [ZnL(AC)]2 (Zn2) were synthesized from 3-(1-(salicyloylhydrazono)ethyl) pyridine (HL). Single crystal X-ray structure analyses showed that complexes Zn1 and Zn2 have a zero-dimensional monomer or dimer structure. Antiproliferative activity studies revealed that Zn1 and Zn2 are both more effective against A549 cells than cisplatin. The results of the reactive oxygen species (ROS) generation assay on A549 cells showed that both Zn1 and Zn2 induced apoptosis through ROS accumulation. The apoptosis-inducing and cell cycle arrest effects of Zn1 and Zn2 on A549 cells indicated that the antitumor effect was achieved through apoptosis induction and inhibition of DNA synthesis by blocking the G0/G1 phase of the cell cycle. What’s more, the results of wound-healing assay showed that Zn1 and Zn2 could inhibit the migration of A549 cells. Western blot analysis further demonstrated that Zn1 and Zn2 induced cell apoptosis through the mitochondrial pathway, in which process, the expression level of cytochrome C, cleaved-PARP, cleaved-caspase 3 and cleaved-caspase 9 proteins increased while pro-caspase 3 and pro-caspase 9 expression decreased. In vivo anticancer evaluation demonstrated that both Zn1 and Zn2 complexes effectively inhibited tumor growth without causing significant toxicity in systemic organs.

Synthesis, characterization, and antibacterial studies of some of first transition series metals and zinc complexes with mixed ligands of trimethoprim-isatin and nitrogen base

Complexes of mixed-ligand Schiff bases [trimetho-prim (TMP) with isatin] (L1) and nitrogen bases [2,2′-bipyridine (bipy)] (L2), [1,10-phenanthroline (phen) (L3)] with metal chlorides: M = Cr3+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+ were prepared and characterized by metal content determination (%), FT-IR, electronic, nuclear magnetic resonance, mass spectroscopy, magnetic susceptibility, conductance measurements and elemental analysis (CHN). The bacterial activity of the ligands and their metal compounds was evaluated via various microorganisms. Infrared spectra of Schiff base showed an azomethine peak shifted in complexes that coincide synthesis and coordination of Schiff base through the nitrogen atom of azomethine C=N) and the oxygen atom of the carbonyl group of L1 with metal ions. L2, L3 (bipy, phen) coordinated through the di imine nitrogen atoms. Conductance dimensions suggested the non-conductance nature of all the compounds except Cr(III) complexes, this outcome fits in with the molar conductance value estimated for 1:1 electrolyte in DMF. Magnetic susceptibility analysis and electronic spectra indicated an octahedral geometry for all complexes. Biological study for prepared compounds have been evaluated towards pathogenic microbes Staphylococcus aureus and Bacillus subtilis. Some compounds have stronger antibacterial action than Schiff base towards tested microbes. KEY WORDS: Antimicrobial, Heterocyclic compounds, Schiff base, Trimethoprim drug, 2,2-Bipyridyl, 1,10-Phenanthroline Bull. Chem. Soc. Ethiop. 2024, 38(4), 1013-1025. DOI: https://dx.doi.org/10.4314/bcse.v38i4.16

Surprising Route to a Monoazaporphyrin and Full Characterization of Its Complexes with Five Different 3d Metals.

In the search for mild agents for the oxidative cyclization of tetrapyrromethane to the corresponding corrole, we discovered a route that leads to a monoazaporphyrin with three meso-CF3 groups. Optimization studies that allowed access to appreciable amounts of this new macrocycle paved the way for the preparation of its cobalt, copper, nickel, zinc, and iron complexes. All complexes were fully characterized by various spectroscopic methods and X-ray crystallography. Their photophysical and electrochemical properties were determined and compared to those of analogous porphyrins in order to deduce the effect of the peripheral N atom. Considering the global efforts for designing efficient alternatives to platinum group metal (PGM) catalysts, they were also absorbed onto a porous carbon electrode material and studied as electrocatalysts for the oxygen reduction reaction (ORR). The cobalt complex was found to be operative at a quite positive catalytic onset potential and with good selectivity for the desirable 4-electrons/4-protons pathway.

Antibacterial [Zn(nicotinamide)2Cl2] complex for the treatment of skin conditions: An experimental-theoretical study of physicochemical, microbiological and in silico pharmacokinetic properties

A dichlorobis(nicotinamide)zinc(II) complex, [Zn(nicotinamide)2Cl2], was crystallized through the slow evaporation method, and its vibrational, electronic, structural, and thermal properties have been characterized. Density functional theory (DFT) was used for the accurate analysis of intramolecular vibrational modes, obtaining chemical reactivity indices and comparative studies of geometric and electronic parameters, including solvation effects in methanol, ethanol, and water, as well as in vacuum. Additionally, the nature and strength of the bonds associated with the coordination sphere (Cl–Zn and N–Zn) were elucidated from the quantum theory of atoms in molecules and natural bond orbital analyses. Powder X-ray diffraction showed that the coordination compound belongs to a monoclinic symmetry with P21/a (C2h5) space group. Thermal analyses revealed that the material is stable up to 200 °C. From DFT calculations, the complex is chemically more stable in solvents compared to vacuum conditions, with the aqueous medium offering greater stability. The chemical stability was also analyzed by infrared and Raman spectroscopy, with the results showing spectral changes mainly for the vibrational spectra obtained in methanol, ethanol, and water against those obtained in vacuum. Biological experiments showed the complex antibacterial activity against Gram-positive and Gram-negative bacteria, mainly against the Cutibacterium acnes ATCC 6919 strain. A computational study of the absorption, distribution, metabolism, excretion (ADME), and drug-likeness were calculated to support the experimental data.

Structural variety of benzimidazole coordinated zinc(II) and cadmium(II) complexes with closo-decaborate anion

The features zinc(II) and cadmium(II) complexation with benzimidazole derivatives Bz1–CH=N–R1 (L1), Bz1–CH2–NH–R1 (L2) (Bz1 is 1-methylbenzimidazole, R1 is 4–methoxyphenyl), and Bz2–N=CH–R2 (L3; Bz2 is 1-propylbenzimidazole, R2 is phenol) in the presence of closo-decaborate anion has been studied. A number of new mixed ligand complexes with different coordination modes of the cluster anion have been obtained and structurally characterized: {Cd(L1)2[B10H10–κ2B1,B2]}∙2CH3CN and {Cd(L2)2[B10H10–κ2B2,B6]} with the [B10H10]2– anion, coordinated by metal atom through the apical (B1B2) or equatorial (B2B6) edge of the boron cage, as well as the first examples of complexes {ZnL2(CH3CN)[B10H10–κ3B1,B2,B3]}, {Zn(Bz2–NH2)2(DMSO)[B10H10–κ3B1,B2,B3]}∙3CH3CN, and {Cd(Bz2–NH2)2(DMF)[B10H10–κ3B1,B2,B3]}∙2CH3CN with facial (B1B2B3) coordination of the closo-decaborate anion. For the first time, theoretical IR spectra have been calculated for cadmium(II) complexes with the coordinated [B10H10]2– anion.

Chemical Investigation of the Calcareous Marine Sponge Pericharax heteroraphis, Clathridine-A Related Derivatives Isolation, Synthesis and Osteogenic Activity.

As a result of screening a panel of marine organisms to identify lead molecules for the stimulation of endochondral bone formation, the calcareous sponge Pericharax heteroraphis was identified to exhibit significant activity during endochondral differentiation. On further molecular networking analysis, dereplication and chemical fractionation yielded the known clathridine A-related metabolites 3-6 and the homodimeric complex (clathridine A)2 Zn2+ (9), together with the new unstable heterodimeric complex (clathridine A-clathridimine)Zn2+ (10). With the presence of the zinc complexes annotated through the LC-MS analysis of the crude extract changing due to the instability of some metabolites and complexes constituting the mixture, we combined the isolation of the predicted molecules with their synthesis in order to confirm their structure and to understand their reactivity. Interestingly, we also found a large quantity of the contaminant benzotriazoles BTZ (7) and its semi-dimer (BTZ)2CH2 (8), which are known to form complexes with transition metals and are used for preventing corrosion in water. All isolated 2-aminoimidazole derivatives and complexes were synthesized not only for structural confirmation and chemical understanding but to further study their bioactivity during endochondral differentiation, particularly the positively screened imidazolone derivatives. Compounds leucettamine B, clathridine A and clathridimine were found to increase type X collagen transcription and stimulate endochondral ossification in the ATDC5 micromass model.

Two robust zinc(II) complexes as multi-functional luminescence sensor for detection of Fe3+, Cr2O72−, and CrO42− ions in water

Two new zinc(II) complexes, namely, [Zn(BBOP)(TPA)0.5]n (1) and [Zn(BBOP)(NDC)·H2O]n (2) (H2TPA = terephthalic acid, H2NDC = 1,4-naphthalene dicarboxylic acid, BBOP = 1,3-bis(benzimidazol-2-yl)-2-oxapropane) are hydrothermally synthesized and characterized. 1 features a 3D 2-fold interpenetrated 3-connected SrSi2-type framework. 2 is a mononuclear Zn(II) complex and further extend into the 3D supramolecular framework by OH⋯O and NH⋯O hydrogen bonding interactions. 1 and 2 both manifest high chemical stability. Two luminescence complexes are excellent sensors for the luminescent detection of Fe3+, Cr2O72−, and CrO42− ions in an aqueous medium. The quenching mechanism of the complexes is also investigated.

Dihydrogen Cleavage by a Zinc-Zinc Bond of a Heteroleptic Dizinc(I) Cation.

Oxidative addition of dihydrogen across a metal-metal bond to form reactive metal hydrides in homogeneous catalysis is known for transition metals but not for zinc(I)-zinc(I) bond as found in Carmona's eponymous dizinconene [Zn2Cp*2] (Cp* = η5-C5Me5). Dihydrogen reacted with the heteroleptic zinc(I)-zinc(I) bonded cation [(L2)Zn-ZnCp*][BAr4F] (L2 = TMEDA, N,N,N',N'-tetramethylethylenediamine, TEEDA, N,N,N',N'-tetraethylethylenediamine; ArF = 3,5-(CF3)2C6H3) under 2 bar at 80 °C to give the zinc(II) hydride cation [(L2)ZnH(thf)][BAr4F] along with zinc metal and Cp*H derived from the intermediate [Cp*ZnH]. DFT calculations show that the cleavage of dihydrogen occurs through a highly unsymmetrical transition state. Mechanistic studies agree with a heterolytic cleavage of dihydrogen as a result of the cationic charge and unsymmetrical ligand coordination. To explore the existence of zinc(I) hydride, thermally unstable hydridotriphenylborate complexes of zinc(I) [(L2)Zn(HBPh3)-ZnCp*] (L2 = TMEDA, TEEDA; TMPDA, N,N,N',N'-tetramethyl-1,3-propylenediamine) have been prepared by salt metathesis and were shown to undergo fast exchange with both BPh3 and [HBPh3]-.