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Two binuclear Gadolinium(III) (Gd) complex [Gd2(L1)2(H2L3)2(NO3)2] (1) and [Gd2(L2)2(H2L3)2(NO3)2] (2) were obtained by using 2‐hydroxybenzaldehyde or 2‐hydroxy‐1‐naphthaldehyde, 2‐aminophenol, pyridin‐2‐ylmethanamine and Gd(NO3)3 ⋅ 6H2O in CH3CN (H2L1=(E)‐2‐((2‐hydroxybenzylidene)amino)phenol, H2L2=(E)‐1‐(((2‐hydroxyphenyl)imino)methyl)naphthalen‐2‐ol, H2L3=pyridin‐2‐ylmethanamine). Structural analysis suggests that all the ligands as protective units protect the central Gd(III) ions at the periphery. Magnetization studies exhibited magnetocaloric effect of 14.45 J ⋅ kg−1 ⋅ K−1 at 4 K under ΔH=7 T for complex 1 and 12.69 J ⋅ kg−1 ⋅ K−1 at 2 K under ΔH=7 T for complex 2. In complexes 1 and 2, although the coordination configurations are the same, the significant difference in MCE may be due to the adjustments of the peripheral ligands leading to changes in the coordination field strength. The electron affinity of the ligands can impact the interaction between the ligands and Gd(III) ions. [ABSTRACT FROM AUTHOR]

The hydrophobic reagent 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR) was investigated as part of a cloud-point extraction (CPE) system for the spectrophotometric determination of Zn(II). In the system, complexes with different stoichiometries, including 1:1 and 2:2 (Zn:HTAR), are formed. Their ground-state equilibrium geometries were optimized at the B3LYP/6-31G level of theory. The obtained structures were then used to calculate vertical excitation energies in order to generate theoretical UV/Vis absorption spectra. The comparison between theoretical and experimental spectra demonstrated that, under optimal conditions, a binuclear complex containing oxygen-bridging atoms is the dominant species. The absorbance was found to be linearly dependent on the concentration of Zn(II) within the range of 15.7 to 209 ng mL−1 (R2 = 0.9996). The fraction extracted (%E), logarithm of the conditional extraction constant (log Kex), and molar absorption coefficient (ε) at λmax = 553 nm were calculated to be 98.3%, 15.9, and 4.47 × 105 L mol−1 cm−1, respectively. The method developed is characterized by simplicity, convenience, profitability, sensitivity, and ecological friendliness. It has been successfully applied to the analysis of pharmaceutical and industrial samples. [ABSTRACT FROM AUTHOR]

Luminescent CuI complexes are an important class of coordination compounds due to their relative abundance, low cost and ability to display excellent luminescence. The title Cu2I2P2S2‐type binuclear complex, di‐μ‐iodido‐bis[(thiourea‐κS)(triphenylphosphine‐κP)copper(I)], [Cu2I2(CH4N2S)2(C18H15P)2], conventionally abbreviated as Cu2I2TPP2TU2, where TPP and TU represent triphenylphosphine and thiourea, respectively, is described. In this complex, each CuI atom adopts a CuI2PS four‐coordination mode and pairs of atoms are connected to each other by two μ2‐I ligands to form a centrosymmetric binuclear cluster. It was also found that the paper‐based film of this complex exhibited obvious luminescence light‐up sensing for pyridine and 4‐methylpyridine. [ABSTRACT FROM AUTHOR]

The dinuclear molecule of the title compound, [Mo2(C9H13)2(CO)6] or [Mo(tBuCp)(CO)3]2 where tBu and Cp are tert-butyl and cyclopentadienyl, is centrosymmetric and is characterized by an Mo—Mo bond length of 3.2323 (3) Å. Imposed by inversion symmetry, the tBuCp and the carbonyl ligands are in a transoid arrangement to each other. In the crystal, intermolecular C—H...O contacts lead to the formation of layers parallel to the bc plane.

The dinuclear mol­ecule of the title compound, [Mo2(C9H13)2(CO)6] or [Mo(tBuCp)(CO)3]2 where tBu and Cp are tert-butyl and cyclo­penta­dienyl, is centrosymmetric and is characterized by an Mo—Mo bond length of 3.2323 (3) Å. Imposed by inversion symmetry, the tBuCp and the carbonyl ligands are in a transoid arrangement to each other. In the crystal, inter­molecular C—H⋯O contacts lead to the formation of layers parallel to the bc plane. [ABSTRACT FROM AUTHOR]

The dinuclear molecule of the title compound, [Mo2(C9H13)2(CO)6] or [Mo(tBuCp)(CO)3]2 where tBu and Cp are tert-butyl and cyclopentadienyl, is centrosymmetric and is characterized by an Mo--Mo bond length of 3.2323 (3) Å. Imposed by inversion symmetry, the tBuCp and the carbonyl ligands are in a transoid arrangement to each other. In the crystal, intermolecular C--H...O contacts lead to the formation of layers parallel to the bc plane. [ABSTRACT FROM AUTHOR]

The hydrogen evolution reaction (HER) has emerged as a focal point in the realm of sustainable energy generation, offering the potential to produce clean hydrogen gas (H2) devoid of pollutants. The pursuit of stable HER electrocatalysts that can reduce our reliance on precious platinum, while still maintaining a high level of catalytic efficiency, presents a significant and ongoing challenge. In this study, we introduce the utilization of a binuclear nickel (II) Schiff base complex known as [Ni]2[L]2 2 for the purpose of HER electrocatalysis. The rational design of this electrocatalyst has yielded optimal HER performance, wherein the strategic placement of electronegative heteroatoms in proximity to the metal centers serves to enhance proton affinity. Consequently, this catalyst manifests outstanding HER activity, characterized by a nearly 100% faradaic efficiency (FE) at an overpotential potential of −0.4 V versus the reverse hydrogen electrode (RHE), sustained catalytic activity over an extended 80 h electrolysis period, and a commendable turnover number (TON) of 0.0006 s−1. [ABSTRACT FROM AUTHOR]

Reaction of copper(I) iodide in pure 2-chloropyrazine leads to the formation of a few crystals of the title compound, [Cu2I2(C4H3ClN2)4] or (CuI)2(2-chloropyrazine)4, which was characterized by single-crystal X-ray diffraction. In its crystal structure, the CuI cations are each tetrahedrally coordinated by two iodide anions and two 2-chloropyrazine ligands and are linked into binuclear complexes consisting of (CuI)2 rings located on centers of inversion. PXRD investigations of a few crystals obtained from the suspension indicate that the title compound is contaminated with a small amount of the 2-chloropyrazine-deficient compound CuI(2-chloropyrazine) already reported in the literature. PXRD investigations prove that the title compound immediately decomposes at room temperature into CuI(2-chloropyrazine) and this might be the reason why no pure samples can be obtained. TDA–TG–MS investigations shows two mass losses, the first of which corresponds to the formation of CuI(2-chloropyrazine), whereas in the second mass loss CuI is formed.

6-Chloro-2-ferrocenyl-1H-benzimidazole and (E)-((4-chloro-2-hydroxyphenylimino)methyl)ferrocene ligands and their Fe(III), Co(II), Cu(II), Zn(II) and Pd(II) complexes were synthesized. The structure of ligands and metal complexes has been investigated by different methods. In addition, magnetic moment, molar conductivity measurements and antibacterial activity of the ligands and the complexes were investigated.

A novel Schiff base has been synthesized from the condensation of the 3‐formyl‐2‐hydroxybenzoic acid and 4‐nitrobenzene‐1,2‐diamine. The new ligand was found to have two coordination sites. So, it has the capability to form mono‐ and binuclear complexes with different metal ions. The free ligand and its mono‐ and binuclear cobalt(II) complexes have been characterized by UV–Visible spectra, IR, elemental analyzes, H1 NMR, conductimetric, thermal, and magnetic measurements. Results indicated that the cobalt(II) ion is attached to the inside coordination site and the second metal ion attached to the outside coordination site. The complexes are all non‐electrolytes, as demonstrated by the molar conductance tests. The thermodynamic parameters of the metal complexes are calculated using Horowitz Metzger and Coats‐Redfern methods. The complexes' bonding properties have also been estimated. Molecular docking was employed to forecast the interaction of the prepared with the Candida‐albicans receptor (1zap). The biological activities of these metal complexes were tested against some bacteria and fungi. It is evident from the biological screening data that the prepared Co(II) binuclear complexes exhibit predominant activity against Candida albicans, Penicillium oxalicum and Escherichia coli, while they have no activity against Micrococcus roseus and Micrococcus luteus. [ABSTRACT FROM AUTHOR]

A binuclear tungsten(0) complex with an asymmetric bridging 1,2-diphosphole ligand was prepared by the photolysis of tungsten hexacarbonyl in the presence of 1-isopropyl-2-phenyl-1,2,5,6-tetrahydroacenaphtho [5,6-cd][1,2]diphosphole. The tungsten complex 1 was characterized by high resolution mass spectrometry, multinuclear NMR spectroscopy (1H, 13C, 31P), and elemental microanalysis. The structure of the trans isomer was resolved by single crystal X-ray diffraction, showing a slight elongation of the P−P bond upon coordination to the W(CO)5 groups. [ABSTRACT FROM AUTHOR]

• Synthesized a novel dinuclear copper(II) complex with distorted octahedral geometry. • Complex shows solvatochromism, ionochromism, halochromism, thermochromism. • Jahn-Teller effect and flexible coordination drive chromotropic behavior. • TDDFT computational studies validate experimental chromotropic behavior and spectra. • Potential applications in sensing technologies and smart materials are demonstrated. A novel dinuclear copper(II) complex, [Cu₂L₂(μ-Cl)₂]Cl₂•4H₂O, was synthesized using a tetradentate hemilabile ligand, 3,3′-((pyridin-2-ylmethyl)azanediyl)dipropanamide (L). The complex was characterized by various spectroscopic techniques, including FT-IR, UV-Vis spectroscopy, elemental analysis, TG-DTA, and conductivity measurements. X-ray crystallography confirmed the formation of the binuclear complex, revealing a dicationic unit with distorted octahedral geometry at the copper centers, bridged by two chloride ions. The coordination environment around each copper ion includes two nitrogen and two oxygen donors from the ligand, along with the bridging chlorides. Notably, the complex exhibits significant chromotropism, including solvatochromism, halochromism, ionochromism, and thermochromism, which are attributed to the Jahn-Teller effect and the flexible coordination environment around the copper centers. Thermal analysis indicates the stability of the complex up to 118°C, with subsequent decomposition occurring in distinct stages. Hirshfeld surface analysis further elucidates the intermolecular interactions within the crystal lattice. Computational studies were conducted using Time Dependent Density Functional Theory (TD-DFT) to gain insights into the nature of the observed chromotropism. The computed absorption spectra closely matched the experimental data, validating the proposed electronic transitions responsible for the chromotropic behavior. The multifaceted chromotropic behavior of this complex highlights its potential applications in sensing technologies and smart materials. The study advances the understanding of chromotropism in metal complexes and provides insights into the design of responsive materials based on transition metal chemistry. [Display omitted] [ABSTRACT FROM AUTHOR]

The binuclear title compound, [Fe2(C28H48N2O2Si4)(CO)6], consists of two central iron(0) atoms, each of them surrounded by a cyclopentadienone moiety and three carbonyl ligands in a three-legged piano-stool shape. Furthermore, the bis(cyclopentadienone) ligand acts as a bridge between the two metal atoms.

The binuclear complex of Pt2 (Stpip) 2L and its corresponding mononuclear complex Pt (Stpip) LH are synthesized in one step by heating the mixture of chloro-bridged Pt (Ⅱ) dimer and StpipH ligand in acetone in the presence of potassium carbonate under reflux condition. The complexes are separated and characterized by ¹H and 31P NMR spectroscpy, high resolution mass spectrometry (HRMS) and X-ray single crystal diffraction. The luminescent properties of the complexes are studied by UV-Vis absorption spectrometer and fluorescent emission spectrometer. Among them, a binuclear complex exhibits strong phosphorescence at 593 and 560 nm in neat solid state and 2% PMMA film, respectively, and the quantum yield in PMMA film reaches 22. 2%. A mononuclear complex exhibits phosphorescence at 524 and 526 nm in neat solid state and 2% (mass percent) PMMA film, respectively, and the quantum yield in PMMA films reaches 38. 7%. The phosphorescence lifetime for both of complexes in two different states are between 0. 99~2. 80 μs. Organic light-emitting diodes (OLEDs) are fabricated by using the complex Pt2 (Stpip) 2L as the light-emitting layer. The results show that the maximum current efficiency of the OLEDs is 25. 50 cd/A, the maximum power efficiency is 15. 41 lm/W, the maximum external quantum efficiency is 8. 19%, and the CIE color coordinates are (0. 48, 0. 50) [ABSTRACT FROM AUTHOR]

Binuclear heteroleptic triple-decker terbium(III) phthalocyaninate (Pc)Tb[(15C5)4Pc]Tb(Pc), where Pc2− is phthalocyaninate dianion and 15C5 is a 15-crown-5 moiety, has been synthesized as a solvent-free powder (1) and a well-defined crystal solvate with o-dichlorobenzene (Pc)Tb[(15C5)4Pc]Tb(Pc)⋅6C6H4Cl2 (2). In the crystal structure of 2, the Tb-N(Pc) distances to the nitrogen atoms in the outer and inner decks are 2.350–2.367(4) and 2.583–2.598(4) Å, respectively, and the Tb–Tb distance is 3.4667(3) Å. The twist angle between the outer and the inner decks is 42.6°. The magnetic properties were studied for both 1 and 2. The χMT magnitude of 23.3 emu⋅K/mol at 300 K indicates a contribution of two TbIII centers with the 7F6 ground state. The χMT product increases with decreasing temperature to reach 38.5 emu⋅K/mol at 2 K. This is indicative of ferromagnetic coupling between TbIII spins in accordance with previous data for triple-decker lanthanide phthalocyaninates of a dipolar nature. Both forms show a single-molecule magnet (SMM) behavior manifesting the in-phase (χ′) and out-of-phase (χ″) AC susceptibility signals in an oscillating field of 3 Oe with estimated effective spin-reversal energy barriers (Ueff) of 222(9) and 93(7) cm−1 for 1 and 2, respectively. The compounds show narrow hysteresis loops in the −1 – +1 kOe range, and the splitting between the zero-field-cooling and field-cooling curves is observed below 6 K. Thus, in spite of similar static magnetic characteristics, each form of the Tb(III) complex shows a different dynamic SMM behavior. [ABSTRACT FROM AUTHOR]

Reaction of copper(I) iodide in pure 2-chloro-pyrazine leads to the formation of a few crystals of the title compound, [Cu2I2(C4H3ClN2)4] or (CuI)2(2-chloro-pyrazine)4, which was characterized by single-crystal X-ray diffraction. In its crystal structure, the CuI cations are each tetra-hedrally coordinated by two iodide anions and two 2-chloro-pyrazine ligands and are linked into binuclear complexes consisting of (CuI)2 rings located on centers of inversion. PXRD investigations of a few crystals obtained from the suspension indicate that the title compound is contaminated with a small amount of the 2-chloro-pyrazine-deficient compound CuI(2-chloro-pyrazine) already reported in the literature. PXRD investigations prove that the title compound immediately decomposes at room temperature into CuI(2-chloro-pyrazine) and this might be the reason why no pure samples can be obtained. TDA-TG-MS investigations shows two mass losses, the first of which corresponds to the formation of CuI(2-chloro-pyrazine), whereas in the second mass loss CuI is formed. [ABSTRACT FROM AUTHOR]

Disentangled ultrahigh molecular weight polyethylene (dis‐UHMWPE) has excellent processability but can be achieved under extreme conditions. Herein, we report ethylene polymerization with the binuclear half‐sandwich scandium complexes C1‐Sc2 and C2‐Sc2 to afford UHMWPE. C1‐Sc2 bearing a short linker shows higher activity and gives higher molecular weight PEs than C2‐Sc2 containing a flexible spacer and the mononuclear Sc1. Strikingly, all UHMWPEs isolated from C1‐Sc2 under broad temperature range (25–120 °C) and wide ethylene pressures (2–13 bar) feature very low degree of entanglement as proved by rheological test, DSC annealing study and SEM. These dis‐UHMWPEs are facilely mediated solid‐state‐process at 130 °C and their tensile strength and modulus reach up to 149.2 MPa and 1.5 GPa, respectively. DFT simulations reveal that the formation of dis‐UHMWPE is attributed to the binuclear synergic effect and the agostic interaction between the active center and the growing chain. [ABSTRACT FROM AUTHOR]

A series of binuclear triphenylantimony(V) bis-catecholato complexes 1–11 of the type (Cat)Ph3Sb-linker-SbPh3(Cat) was prepared by a reaction of the corresponding mononuclear catecholates (Cat)SbPh3 with a neutral bidentate donor linker ligands pyrazine (Pyr), 4,4′-dipyridyl (Bipy), bis-(pyridine-4-yl)-disulfide (PySSPy), and diazobicyclo[2,2,2]octane (DABCO) in a dry toluene: Cat = 3,6-di-tert-butyl-catecholate (3,6-DBCat), linker = Pyr (1); PySSPy (2); Bipy (3); DABCO (4); Cat = 3,5-di-tert-butyl-catecholate (3,5-DBCat), linker = Bipy (5); DABCO (9); Cat = 4,5-(piperazine-1,4-diyl)-3,6-di-tert-butylcatecholate (pip-3,6-DBCat), linker = Bipy (6); DABCO (10); Cat = 4,5-dichloro-3,6-di-tert-butylcatecholate (4,5-Cl2-3,6-DBCat), linker = Bipy (7); DABCO (11); and Cat = 4,5-dimethoxy-3,6-di-tert-butylcatecholate (4,5-(MeO)2-3,6-DBCat), linker = Bipy (8). The same reaction of (4,5-Cl2-3,6-DBCat)SbPh3 with DABCO in an open atmosphere results in a formation of 1D coordination polymer {[(4,5-Cl2-3,6-DBCat)SbPh3·H2O]·DABCO}n (12). Bis-catecholate complex Ph3Sb(Cat-Spiro-Cat)SbPh3 reacts with Bipy as 1:1 yielding a rare macrocyclic tetranuclear compound {Ph3Sb(Cat-Spiro-Cat)SbPh3∙(Bipy)}2 (13). The molecular structures of 1, 3, 4, 5, 8, 10, 12, and 13 in crystal state were established by single-crystal X-ray analysis. Complexes demonstrate different types of relative spatial positions of mononuclear moieties. The nature of chemical bonds, charges distribution, and the energy of Sb...N interaction were investigated in the example of complex 5. The electrochemical behavior of the complexes depends on the coordinated N-donor ligand. The coordination of pyrazine, Bipy, and PySSPy at the antimony atom changes their mechanism of electrooxidation: instead of two successive redox stages Cat/SQ and SQ/Cat, one multielectron stage was observed. The coordination of the DABCO ligand is accompanied by a significant shift in the oxidation potentials of the catecholate ligand to the cathodic region (by 0.4 V), compared to the initial complex. [ABSTRACT FROM AUTHOR]

Synthesis, characterization and structures of binuclear 'bicyclo' type silver(I), copper(I) complexes of Imidazo[1,2- α ]pyrimidine are described. [Display omitted] • Synthesis of Imidazopyrimidine under neat condition. • Transmetallation reaction capitalized to get Cu(I) complex. • Bicyclo type of complex bearing Ag(I) and Cu(I). • Closed shell d10-d10 interactions leads to luminescence. Imidazo[1,2- α ]pyrimidine, (1) was synthesized by a modified pathway through a neat reaction; corresponding Ag(I) complex (2) and Cu(I) complex (3) have been synthesized at room temperature and characterized by a series of spectroscopic techniques. Complex 2 has been synthesized after floating in the acetonitrile solution of ligand 1 into AgPF 6 ; Cu(I) complex (3) has been synthesized by the transmetallation method. Finally, the solid state structure of 2 has been established by single crystal X-ray diffraction studies. The molecule 2 possesses 'bicyclo' like geometry. The formulation of 3 was supported by elemental analysis and HR-mass spectral studies. Interestingly, single crystal X-ray diffraction studies establish 2 as a dinuclear Ag(I) complex where each Ag(I) is coordinating by three N pym (pym = pyrimidine) from each ligand. Though the ligand is nonluminescent, yet Ag(I) complex (2) and Cu(I) complexes (3) are luminescent this may be due to closed cell d10-d10 interactions. DFT studies were also done to insight into the structures which also support the weak Ag(I)--Ag(I) and Cu(I)--Cu(I) interactions. [ABSTRACT FROM AUTHOR]

The photoluminescence properties of novel bis- N -carboxamide ligand and its Cu(II) complex were studied. Molecular docking was utilized to describe the interactions between the ligand and the EGFR tyrosine kinase enzyme. Moreover, all compounds were investigated cytotoxic activity on HTB-54 and BEAS-2B lung cell lines. [Display omitted] A new bis- N -carboxamide ligand (H 2 L) was synthesized from reaction of dibenzoylaceticacid- N -carboxyethylamide with p -phenylenediamine. The binuclear metal complex of the new ligand was prepared from Cu(II) salt. The structures of the synthesized compounds were confirmed using elemental analysis, UV–Vis, IR, 1H NMR, 13C NMR, TGA, and LC-MS/MS spectroscopy. The stoichiometric ratio of H 2 L-Cu2+ was found to be 2:2 (L:M) by the use of Job's graph. The photoluminescence properties of the ligand and Cu(II) complex was investigated in DMF solution. The ligand is highly emissive upon excitation at 291 nm. The coordination of the ligand to the Cu(II) ion caused quenching of the emission band along with the red shift. The Cu complex did not affect healthy cells at the dose administered, but showed toxic effects at concentrations close to the ligand, suggesting that the Cu complex may be a potential anticancer drug. In addition, molecular docking results indicate that amino acids Asp776 and Met742 generated π-Anionic and π-Sulfur interactions with the phenolic portions of the molecule. There was a π-sigma connection between the ligand and the amino acid Leu820, and a π-alkyl interaction between the ligand and the amino acids Val702 and Ala719. [ABSTRACT FROM AUTHOR]

A new binuclear copper(II) complex Cu2(Piv)4(L)2, where Piv– = pivalate, L = 2,6-di-tert-butyl-4-(3,5-bis(4-pyridyl)pyridyl)phenol, was synthesized, and its molecular and crysral structures were determined at temperatures of 160, 173, and 296 K (CIF files CCDC no. 2144104, 2144105, and 2144106, respectively). Cyclic voltammetry measurements revealed three irreversible oxidation processes in the potential range of 0.5–1.2 V versus Fc+/Fc. Analysis of the temperature dependence of the magnetic susceptibility of Cu2(Piv)4(L)2 showed that antiferromagnetic interactions of Cu2+ ions predominate in the complex. It was found that the oxidation of Cu2(Piv)4(L)2 upon grinding with PbO2 or treatment of a solid sample with an aqueous solution of K3[Fe(CN)6] affords long-lived phenoxyl radical, which can be detected by ESR spectroscopy. [ABSTRACT FROM AUTHOR]

The design and systematic investigation of an electrocatalyst is crucial in ensuring proper benchmarking of the catalyst developed. This perspective has led to molecular catalysts developed from N-heterocyclic carbene (NHC) metal complexes for electrocatalytic applications. Among the array of electrocatalytic applications available, hydrogen evolution reaction (HER) is at the forefront due to the ever-increasing demand for cleaner and sustainable energy. This work is focussed on the development of binuclear metal-NHC complexes from bis-{4-(2,6-diethylphenyl)-1,2,4-triazole} with a propyl spacer and hexafluorophosphate counterion. The NHC precursor and binuclear silver complexes prepared have been elucidated by single-crystal X-ray diffraction. An assessment of the binuclear complex bearing the same ligand with nickel(II) resulted in the formation of a counter held nickel derivative. The electrocatalytic performance of these metal organic derivatives in HER is evaluated along with their electrochemical impedance spectral discussion. [ABSTRACT FROM AUTHOR]

Recent scientific publications demonstrate a new approach to modeling catalysts that mimic heme-containing enzymes. It involves the use of μ-oxo, μ-nitrido, and μ-carbido dimeric transition metal complexes as promising mimetics. The high catalytic activity of μ-nitrido dimeric iron(III,IV) complexes with porphyrin-type macrocycles, mediated by the formation of high-valence oxo forms similar to the redox site of oxidative enzymes, stimulates interest in such compounds. In this review, special attention is focused on studies aimed at scrutinizing the chemical principles of the formation of different types of highly oxidized oxo forms of μ-nitrido and μ-carbido dimeric iron(IV) and ruthenium(IV) complexes and modulation of their reactivity. Here data on the spectral, coordination, and redox properties of μ-nitrido and μ-carbido dimeric iron(IV) and ruthenium(IV) complexes are summarized, their comparative analysis is performed, and the possibility of using these compounds as a molecular platform for modeling oxidative enzymes is demonstrated. It is noted that the bimetallic structure is flexible and has significant potential for further development and fine tuning of properties through the inclusion of various ligands, metals, and bridging groups in the structure. [ABSTRACT FROM AUTHOR]

The reaction of the hexathiapyrazinophane ligand, 2,5,8,11,14,17-hexathia-[9.9](2,6,3,5)-pyrazinophane (L1), with copper(II) dibromide led to the formation of a binuclear complex, [μ2-2,5,8,11,14,17-hexathia-[9.9](2,6,3,5)-pyrazinophane]bis[bromidocopper(II)] dibromide, [Cu2Br2(C16H24N2S6)]Br2, (I). The complex possesses inversion symmetry with the pyrazine ring being situated about a center of symmetry. The ligand coordinates to the copper(II) atom in a bis-tetradentate manner and the copper atom has a fivefold NS3Br coordination environment with a distorted shape. The reaction of ligand L1 with copper(I) iodide also gave a binuclear complex, which is bridged by a Cu2I2 unit to form a two-dimensional coordination polymer, poly[[μ2-2,5,8,11,14,17-hexathia-[9.9](2,6,3,5)-pyrazinophane]tetra-μ-iodido-tetracopper(I)], [Cu4I4(C16H24N2S6)]n, (II). The binuclear unit possesses inversion symmetry with the pyrazine ring being located about a center of symmetry. The Cu2I2 unit is also located about an inversion center. The two independent copper(I) atoms are both fourfold coordinate. That coordinating to the ligand L1 in a bis-tridentate manner has an NS2I coordination environment and an irregular shape, while the second copper(I) atom, where L1 coordinates in a bis-monodentate manner, has an SI3 coordination environment with an almost perfect tetrahedral geometry. In the crystal of I, the cations and Br− anions are linked by a number of C—H...S and C—H...Br hydrogen bonds, forming a supramolecular network. In the crystal of II, the two-dimensional coordination polymers lie parallel to the ab plane and there are no significant inter-layer contacts present.

Three new complexes of Cu(II), Zn(II) and Cd(II) with bis(2-pyridyl)-di(4-methoxyphenyl)ethene (KT1), bis(µ2-chloro)-dichloro-bis(2-(2,2-di(4-methoxyphenyl)-1-(pyridin-2-yl)vinyl)pyridine)-di-copper(II) (CuKT1), dichloro-2-(2,2-di(4-methoxyphenyl)-1-(pyridin-2-yl)vinyl)pyridine-zinc(II) (ZnKT1) and hexakis(µ2-chloro)-dichloro-tetrakis(2-(2,2-di(4-methoxyphenyl)-1-(pyridin-2-yl)vinyl)pyridine)-tetra-cadmium(II) (CdKT1) were synthesized and characterized by IR spectroscopy, 1H NMR spectroscopy and single-crystal X-ray diffraction. The results reveal that ZnKT1 is a mononuclear complex, while CuKT1 and CdKT1 are binuclear and tetranuclear complexes, respectively. The central metal ions are surrounded by two N atoms of bis(2-pyridyl)-di(4-methoxyphenyl)ethene and Cl− ions including pendant and bridged ones. In the ZnKT1 complex, a distorted tetrahedral geometry is formed with Zn(II) as central ion and two chloride ions plus two nitrogen atoms of KT1 as surrounding atoms. CuKT1 is a binuclear complex with two square pyramids formed around the two Cu(II) ions. CdKT1 is a tetranuclear complex with two Cd(II) cations having coordination number six (distorted octahedral geometry) and the other two having coordination number five (distorted trigonal-bipyramidal geometry). The anticancer activity tests on four cancer cell lines, including KB, Hep-G2, Lu and MCF-7, show that ZnKT1 and CuKT1 are active against Hep-G2 and Lu but do not considerably damage KB and MCF-G7. CuKT1 has a considerable effect on two cancer cell lines, Hep-G2 and Lu, with IC50 values of 16(2) and 13(1) μM, respectively. CdKT1 exhibits excellent activity against all four cancer cell lines, with IC50 values ranging from 3.5(2) to 8.8(5) μM, which are lower than those of cisplatin. These complexes exhibit low cytotoxic activity on the normal cell line HEK-293A with IC50 values ranging from 10(1) to 74(5) µM. [ABSTRACT FROM AUTHOR]

Binuclear heteroleptic triple-decker terbium(III) phthalocyaninate (Pc)Tb[(15C5)4Pc]Tb(Pc), where Pc2− is phthalocyaninate dianion and 15C5 is a 15-crown-5 moiety, has been synthesized as a solvent-free powder (1) and a well-defined crystal solvate with o-dichlorobenzene (Pc)Tb[(15C5)4Pc]Tb(Pc)⋅6C6H4Cl2 (2). In the crystal structure of 2, the Tb-N(Pc) distances to the nitrogen atoms in the outer and inner decks are 2.350–2.367(4) and 2.583–2.598(4) Å, respectively, and the Tb–Tb distance is 3.4667(3) Å. The twist angle between the outer and the inner decks is 42.6°. The magnetic properties were studied for both 1 and 2. The χMT magnitude of 23.3 emu⋅K/mol at 300 K indicates a contribution of two TbIII centers with the 7F6 ground state. The χMT product increases with decreasing temperature to reach 38.5 emu⋅K/mol at 2 K. This is indicative of ferromagnetic coupling between TbIII spins in accordance with previous data for triple-decker lanthanide phthalocyaninates of a dipolar nature. Both forms show a single-molecule magnet (SMM) behavior manifesting the in-phase (χ′) and out-of-phase (χ″) AC susceptibility signals in an oscillating field of 3 Oe with estimated effective spin-reversal energy barriers (Ueff) of 222(9) and 93(7) cm−1 for 1 and 2, respectively. The compounds show narrow hysteresis loops in the −1 – +1 kOe range, and the splitting between the zero-field-cooling and field-cooling curves is observed below 6 K. Thus, in spite of similar static magnetic characteristics, each form of the Tb(III) complex shows a different dynamic SMM behavior.

The title compound, (NH4)4[W2(C10H12N2O8)O6]·4H2O, was obtained from a mixture of tungstic acid, ammonia and ethylenediaminetetraacetic acid (H4edta) in a 2:4:1 ratio. The anion of the complex contains two WO3 units and one bridging edta4− ligand. Each central metal atom is tridentately coordinated by nitrogen and two carboxylate groups of the edta4− ligand, together with the three oxido ligands, producing a distorted octahedral coordination environment around each tungsten atom. The center of the carbon–carbon bond of the ethylene bridge represents a crystallographic inversion center. The crystal structure consists of a three-dimensional supramolecular framework built up by the dinuclear cations, the ammonium counter-ions and the solvent water molecules via hydrogen bonds of the N—H...O and O—H...O type.

The molecular mechanism by which electron transfer (ET) is coupled to proton pumping in cytochrome oxidase is one of the main unsolved problems in biochemistry. Particularly, the nature and position of the proton-loading site is under dispute. The CuB complex has three ligated histidines, whereas only His290 and His291 are ionizable sites with the same pKa values in aqueous solution, but apparently quite different ones within the enzyme. Earlier, a model of proton pumping with the central role of His290 was proposed. Recent calculations indicate that the His291 ligand of the CuB center might play the role of the pumping element, since its protonation state depends on the oxidation state of the binuclear complex (BNC). The present electrostatic study was applied to assess the role of the protein environment on the acidity of the two histidines. Their pKa values and effects of different energy terms were evaluated to discover the nature of their diverse behavior in the enzyme. Here, a new set of pKa values for the non-standard model compounds within the BNC was applied. The enhanced results are compared with results of previous studies in the light of the plausible proton pumping mechanism. The obtained microscopic and apparent pKa values in the oxidized state of BNC are virtually the same, indicating that deprotonated form of His291 accounts for the large pKa increase of His290, since then both titratable sites on then CuB center cannot simultaneously be in the charged state. The present results support the underlined His291 pumping model.

The reaction of zinc chloride with 2-benzylideneamino-5-methylphenol (LH), a bidentate Schiff base, in 1 : 1 molar ratio in the presence of triethylamine gives the ionic complex [Et3NH]+[LZnCl2]– (I). The reaction between the zinc salt (chloride or acetate) and LH in 1 : 2 ratio results in complete displacement of the zinc salt anions to give bis-o-iminophenolate ZnL2 (II), which exists in the crystalline state as the (ZnL2)2 dimer formed via μ-bridging oxygen atoms of two out of the four o-iminophenolate ligands. The molecular structure of ligand LH and complexes I and (II·CDCl3)2 was established by X-ray diffraction (CIF files CCDC nos. 2052647 (LH), 2052645 (I), 2052646 (II·CDCl3)2). [ABSTRACT FROM AUTHOR]

The method for transforming antiferromagnetic exchange interaction into the ferromagnetic one has been proposed for binuclear coordination compounds, which contain dimers consisting of iron or rare earth ions with arbitrary spins and having identical electronic configurations. The method is based on the time-reversal symmetry violation at isomorphic substitution of one of dimer’s ions by a “time-reversed” ion, when the spin projection operators of only one of dimer’s ions are reversed. Restoration of broken symmetry accompanied by its transformation into combined time-reversal symmetry is caused by sign reversing of exchange interaction constant J at isomorphic substitution. Experimental data confirm the proposed way of inverting the sign of J. The method for controlled synthesis of binuclear coordination compounds using specific isomorphic substitutions with “time-reversed” ions allows extending the class of coordination compounds characterized by ferromagnetic exchange interaction.

The title complex, [Lu2(C17H28O4P)6]·2C7H16, was formed in the reaction between potassium 2,6-di-tert-butyl-4-methylphenyl ethyl phosphate, [K(2,6-tBu2-4-MeC6H2-O)(EtO)PO2], and LuCl3(H2O)6 in water, followed by vacuum drying and recrystallization from heptane. Its crystal structure has triclinic (P\overline{1}) symmetry at 120 K. The lutetium tris(phosphate) complex has a binuclear [Lu2(μ-OPO)4] core and the organophosphate ligand exhibits κ2O,O′ terminal and μ2-κ1O:κ1O′ bridging coordination modes with the LuIII ion being sixfold coordinated. The complex is of interest as a precatalyst in the acrylonitrile polymerization process and displays good catalytic activity under mild conditions.

New bis-o-benzoquinones (3,5-Q)-6-CH2O–(CH2)n–OCH2-6-(3,5-Q) (n = 2 (L1), 4 (L2), and 6 (L3)) and (3,5-Q)-6-(CH2OCH2)3-6-(3,5-Q) (L4) (3,5-Q is 3,5-di-tert-butyl-o-benzoquinone) with various diol spacers have been synthesized and characterized. The oxidative addition of SbPh3 to these bis-o-benzoquinones affords binuclear triphenylantimony(V) bis(catecholate) complexes Ph3Sb(3,5-Cat)-6-CH2O–(CH2)n–OCH2-6-(3,5-Cat)SbPh3 (I–III, respectively) and Ph3Sb(3,5-Cat)-6-(CH2OCH2)3-6-(3,5-Cat)SbPh3 (IV) (3,5-Cat is 3,5-di-tert-butyl catecholate). The molecular structures of quinones L1–L4 and bis(catecholate) complex I in the crystalline state were determined by X-ray diffraction analysis (CIF files CCDC nos. 1998601 (L1), 1998602 (L2), 1998603 (L3), 1998604 (L4), and 1998605 (I ∙ n-pentane)). [ABSTRACT FROM AUTHOR]

The reaction of the hexa­thia­pyrazino­phane ligand, 2,5,8,11,14,17-hexa­thia-[9.9](2,6,3,5)-pyrazino­phane (L1), with copper(II) dibromide led to the formation of a binuclear complex, [μ2-2,5,8,11,14,17-hexa­thia-[9.9](2,6,3,5)-pyrazino­phane]bis­[bromi­docopper(II)] dibromide, [Cu2Br2(C16H24N2S6)]Br2, (I). The complex possesses inversion symmetry with the pyrazine ring being situated about a center of symmetry. The ligand coordinates to the copper(II) atom in a bis-tetra­dentate manner and the copper atom has a fivefold NS3Br coordination environment with a distorted shape. The reaction of ligand L1 with copper(I) iodide also gave a binuclear complex, which is bridged by a Cu2I2 unit to form a two-dimensional coordination polymer, poly[[μ2-2,5,8,11,14,17-hexa­thia-[9.9](2,6,3,5)-pyrazino­phane]tetra-μ-iodido-tetra­copper(I)], [Cu4I4(C16H24N2S6)]n, (II). The binuclear unit possesses inversion symmetry with the pyrazine ring being located about a center of symmetry. The Cu2I2 unit is also located about an inversion center. The two independent copper(I) atoms are both fourfold coordinate. That coordinating to the ligand L1 in a bis-tridentate manner has an NS2I coordination environment and an irregular shape, while the second copper(I) atom, where L1 coordinates in a bis-monodentate manner, has an SI3 coordination environment with an almost perfect tetra­hedral geometry. In the crystal of I, the cations and Br− anions are linked by a number of C—H···S and C—H···Br hydrogen bonds, forming a supra­molecular network. In the crystal of II, the two-dimensional coordination polymers lie parallel to the ab plane and there are no significant inter-layer contacts present. [ABSTRACT FROM AUTHOR]

Bistability of the proposed [(phenanthroline)2FeII/III–(terephthalate)–CoIII/II(phenanthroline)2]3+ binuclear complex, arising from intramolecular FeII/III ↔ CoIII/II charge transfer, is investigated based on energetics, geometries, atomic charges, electric polarizabilities, and IR and UV-Vis spectra obtained computationally at (TD)DFT-B3LYP/LANL2DZ level of theory. Two distinct stable states are obtained which have different characteristics, including structures, charge distributions, and spectroscopic properties. Also, the well-defined first-order saddle point obtained between these two states using the QST3 search method, having a 1.182 eV activation (barrier) energy for the FeIICoIII → FeIIICoII reaction, furthermore approves bistability in this complex. This value of activation energy suggests that switching between the two charge distribution states FeII–CoIII and FeIII–CoII in this complex may be induced by electric field and/or infrared radiation, and thus, it can be candidate as an infrared radiation- or electric field-driven molecular two-state switch. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new family of binuclear ruthenium(III) complexes has been synthesized. • Rhombic distortion of an octahedral geometry around metal is identified. • Facile one-pot aldehyde to amide transformation is investigated. • Present result indicates the excellent conversion of aldehydes to amides. A series of new binuclear ruthenium(III) complexes [ Ru 2 Cl 4 (EPh 3) 4 (L)] (E = P or As) were successfully synthesized from 1:2 mol ratio of bi-nucleating ligand precursors (L 1 H 2 - L 3 H 2) and [RuCl 3 (EPh 3) 3 ] in benzene for 6 h. The complexes were characterized by elemental analysis, FT-IR, UV–vis, magnetic susceptibility measurements and EPR spectroscopy methods. Rhombic distortion (gx ≠ gy ≠ gz) around the ruthenium ion was confirmed by EPR spectra in liquid nitrogen temperature. Catalytic activity of the facile one pot amidation reaction has been developed. The complex [Ru 2 Cl 4 (AsPh 3) 4 (L 1)](4) was found to possess excellent conversion up to 100 % of amide in toluene with the presence of hydroxylamine hydrochloride and NaHCO 3 at 110 °C in 2 h. The effect of time, temperature, solvents and different catalytic loading experiments was also investigated. [ABSTRACT FROM AUTHOR]

Syntheses and structural elucidations of a series of chalcogen stabilized binuclear complexes of group 5 and 6 transition metals have been described. Room temperature reaction of [Cp*CrCl]2 (Cp* = η5-C5Me5) with Li[BH3(SePh)] afforded a Se inserted binuclear chromium complex, [(Cp*Cr)2(µ-Se2SePh)2], 1. In an attempt to make the analogous complexes with heavier group 6 metals, reactions of [Cp*MCl4] (M = Mo and W) with Li[BH3(SePh)] were carried out that yielded Se inserted binuclear complexes [(Cp*M)2(µ-Se)2(µ-SePh)2], 2 and 3 (2: M = Mo and 3: M = W) along with known [(Cp*M)2B5H9], 4a–b (4a: M = Mo and 4b: M = W). Similarly, the reactions of [Cp*NbCl4] with Li[BH3(EPh)] (E = S or Se) followed by thermolysis led to the formation of binuclear chalcogen complexes [(Cp*Nb)2(µ-E2)2], 5 and 6 (5: E = S and 6: E = Se) and known [(Cp*Nb)2(B2H6)2], 7. All these complexes have been characterized by 1H and 13C NMR spectroscopy and mass spectrometry. The structural integrity of complexes 1, 3, 5 and 6 was established by the X-ray diffraction studies. The DFT studies further exemplify the bonding interactions present in these complexes, especially the multiple bond character between the metals in 1–3. The syntheses and structural characterizations of three chalcogen-bridged bimetallic complexes of group 5 and 6 metals, such as [(Cp*Nb)2(µ-E2)2] (E = S and Se) (right), [(Cp*Cr)2(µ-Se2SePh)2] (centre) and [(Cp*M)2(µ-Se)2(µ-SePh)2], (M = Mo and W) (left) are reported. [ABSTRACT FROM AUTHOR]

In this work we present the synthesis, and experimental and theoretical analysis of a binuclear nickel(II) complex coordinated to a new phthalazine dihydrazone-based ligand. Single-crystal X-ray diffraction analysis of the metal complex shows that the coordination geometry around each nickel(II) atom is distorted octahedral. DFT calculations predict that the magnetic exchange coupling constant of the binuclear nickel(II) complex is predominantly anti-ferromagnetic. [ABSTRACT FROM AUTHOR]

Two new binuclear copper (II) complexes with chloride and bromide bridges were synthesized and characterized. The complexes exhibit solvatochromism and thermochromism. The observed chromotropism is due to the Cu-X (X=Cl, Br) band dissociation in the solution. [Display omitted] In this study, two novel chromotropic binuclear copper(II) complexes were introduced. The complexes were denoted as [LCu(μ-Cl)Cl] 2 , 1 and [LCu(μ-Br)Br] 2 , 2 with L representing the chelating ligand N,N -dimethyl- N' -(9-methylanthracenyl)ethylenediamine. To investigate the structures of these complexes, various analytical techniques were employed, including FT-IR, EPR, UV–Vis spectroscopy, TG-DTA, molar conductivity measurements, and elemental analysis. The geometrical property of [LCu(μ-Br)Br] 2 was determined using X-ray crystallography, while the intermolecular interactions were studied through Hirshfeld surface analysis. The characterization data provided strong evidence supporting the proposed binuclear structure, wherein two copper (II) centers are connected by two halogen bridges. Remarkably, these complexes exhibit solvatochromism and thermochromism properties, displaying a diverse range of colors in solutions with varying polarities and/or temperatures. Experimental findings suggest that the observed chromotropism can be attributed to the substitution of solvent molecules with the coordinated halogens in the complexes. [ABSTRACT FROM AUTHOR]

The reaction of Cp(CO)2FeI with 2-ethynylpyridine under Sonogashira conditions [5% PdCl2(PPh3)2, 10% CuI, THF–NEt3 (2:1)] afforded the title binuclear μ-pyridylvinylidene FePd complex (FePd1) as a benzene solvate, [FePd(C5H5)(C7H5N)I(CO)2]·C6H6, in a very low yield rather than the expected iron o-pyridylethynyl complex Cp(CO)2Fe—C[triple-bond]C-(2-C5H4N). The Fe and Pd atoms in FePd1 are bridged by carbonyl and pyridylvinylidene ligands, the pyridyl N atom being bonded to the palladium atom. The use of equimolar amounts of PdCl2 increases the yield of FePd1 to 12%. The reaction pathway leading to FePd1 is proposed.

The aim of this work is to enable increased production of aromatics by the use of salen-porphyrin complex (ZnPSC6) as a binuclear catalyst for the catalytic oxidation of Indulin AT lignin. Catalytic activity was enhanced by the increase in active sites, as confirmed by the results observed in the conversion of lignin model compounds and Indulin AT lignin compared with processes using the mononuclear complexes Zn(salen) and Zn(Phe-TPP). The yields of long and convoluted aromatics from the catalytic oxidation of Indulin AT lignin with ZnPSC6 reached high values after reaction at 80°C for 24 h. Notably, the formation of vanillin was promoted by the increase in active sites over ZnPSC6. This was followed by a significant decrease of β-O-4 linkages and refractory condensed substructures in the lignin, induced by ZnPSC6. This may be expected to be an important area for further study. [ABSTRACT FROM AUTHOR]

The method for transforming antiferromagnetic exchange interaction into the ferromagnetic one has been proposed for binuclear coordination compounds, which contain dimers consisting of iron or rare earth ions with arbitrary spins and having identical electronic configurations. The method is based on the time-reversal symmetry violation at isomorphic substitution of one of dimer's ions by a "time-reversed" ion, when the spin projection operators of only one of dimer's ions are reversed. Restoration of broken symmetry accompanied by its transformation into combined time-reversal symmetry is caused by sign reversing of exchange interaction constant J at isomorphic substitution. Experimental data confirm the proposed way of inverting the sign of J. The method for controlled synthesis of binuclear coordination compounds using specific isomorphic substitutions with "time-reversed" ions allows extending the class of coordination compounds characterized by ferromagnetic exchange interaction. [ABSTRACT FROM AUTHOR]

Platinum(II) complexes featuring conjugated aromatic ligands are widely studied in the context of luminescence. Many such compounds have been discovered that display intense phosphorescence from triplet excited states, offering potential applicability to numerous areas of contemporary interest, including as phosphors for light-emitting devices and imaging agents in cell biology. Aside from the large number of mononuclear Pt(II) complexes that have been reported in the context of luminescence, there are several examples of multinuclear systems – ones that incorporate two or more Pt(II) ions or Pt(II) in combination with other platinum group metal ions. The introduction of a second metal ion can lead to very different luminescence properties compared to the mononuclear analogues. This review aims to provide an overview of some of the key features of multinuclear Pt(II) complexes and their luminescence. It proves to be convenient to subdivide the examples into three classes, according to whether or not there are significant intramolecular interfacial interactions between the square-planar units. In some cases (Class A), for example with aromatic bridging ligands, the units are rigidly held apart from one another and no such intramolecular interactions are possible. In some such complexes, however, the presence of a second metal ion can nevertheless lead to very different properties compared to mononuclear analogues. In particular, recent work has shown that large red shifts in absorption and emission can be accompanied by an increase in the phosphorescence radiative rate constant, offering a way to efficient red and near-infrared emitters. In Class B, on the other hand, the planar Pt(II) units are rigidly held in a conformation that facilitates interfacial interactions. In many cases they involve overlap of Pt 5d z2 and 6p z orbitals, leading to the generation of low-energy 3 MMLCT excited states similar to those seen in aggregates of mononuclear Pt(II) complexes. Finally, complexes in Class C – of which there are very many and we cover only a selection of examples – are those in which there is some flexibility in the linkers between the Pt(II) units. They may display dual emission both from excited states that resemble those of the isolated units, and from lower-energy excited states similar to aggregates or excimers, owing to the ability of the Pt(II) moieties to approach one another in the appropriate conformation. [ABSTRACT FROM AUTHOR]

Reaction of the thallium salt Tl[7,8-Me 2 -10-SMe 2 -7,8- nido -C 2 B 9 H 8 ] with [(cod)RhCl] 2 in THF furnishes new rhodacarborane 1,2-Me 2 -3,3-(cod)-8-SMe 2 -3,1,2 -closo -RhC 2 B 9 H 8 ( 1 ). The latter undergoes 1,2 → 1,7 carbon atom isomerization upon reflux in o -xylene for 5 h producing complex 1,8-Me 2 -2,2-(cod)-11-SMe 2 -2,1,8- closo -RhC 2 B 9 H 8 ( 2 ). Reaction of complex 2 with 1 equiv of I 2 in benzene results in a loss of the cod ligand and formation of product 3 , consisting of cationic [(1,8-Me 2 -11-SMe 2 - closo -2,1,8-RhC 2 B 9 H 8 ) 2 I 3 ] + ( 3a + ) and anionic [(1,8-Me 2 -11-SMe- closo -2,1,8-RhC 2 B 9 H 8 ) 2 I 3 ] − ( 3b – ) iodide species. In contrast, unisomerized analog 3,3-(cod)-8-SMe 2 - closo- 3,1,2-RhC 2 B 9 H 10 reacts with I 2 affording dimeric iodide [3,3-I 2 -8-SMe 2 - closo- 3,1,2-RhC 2 B 9 H 10 ] 2 ( 5 ). The structures of 2 and 5 were determined by a single crystal X-ray diffraction. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of a novel symmetrical Schiff base ligand N,Nʹ-bis(4-hydroxysalicylidene)-1,4-phenylenediamine (BHSP) was presented in this study and characterized by FT-IR, NMR ( 1 H and 13 C) and UV–Vis spectroscopy experimentally and theoretically. Also a series of binuclear Co(II), Ni(II), Cu(II) and Zn(II) complexes of BHSP ligand have been synthesized by conventional sequential route in 1:1 equivalent of L:M ratio and characterized by routine physicochemical characterizations. The molecular geometry and vibrational frequencies of the BHSP in the ground state were calculated by using density functional theory (DFT) B3LYP method invoking 6-31G(d,p) and 6–31++G(d,p) basis sets. To study different conformations of the molecule, potential energy surface (PES) scan investigations were performed. The energetic behavior of the ligand compound (BHSP) in solvent media has been examined using B3LYP method with the 6-31G(d,p) and 6–31++G(d,p) basis sets by applying the polarized continuum model (PCM). In addition, DFT calculations of the BHSP ligand, molecular electrostatic potential (MEP), contour map, natural bond orbital (NBO) analysis, frontier molecular orbitals (FMO) analysis, NMR analysis and TD-DFT calculations were conducted. The calculated properties are in agreement with the available experimental data and closely related molecule BSP. The calculated results show that the optimized geometry can well reproduce the crystal structural parameters. [ABSTRACT FROM AUTHOR]