Density Functional Theoretical Calculations Research Articles

Design and synthesis of new salicylhydrazone tagged indole derivative for fluorometric sensing of Zn2+ ion and colorimetric sensing of F− ion: Applications in live cell imaging

A novel, bifunctional, colorimetric, highly selective and sensitive “turn-on” fluorescent probe, 2-((E)-(((E)-(5-bromo-1H-indol-3-yl) methylene) hydrazono) methyl) phenol (IHP) has been designed and synthesized for the detection of Zn2+/F− ions in DMSO: H2O (9:1, v/v) medium. The probe IHP exposed an excellent fluorescence enhancement towards Zn2+ ion owing to the inhibition of ESIPT with concurrent enhancement of LMCT operated on IHP. Upon addition of F− ion, the probe IHP displayed an obvious colorimetric change and it can be simply observed by naked eye. Further, 1:1 binding stoichiometric ratio of probe with Zn2+/F− ions was confirmed via Job’s plot and highly supported by 1H NMR titration and 19F NMR analysis for F− ion. The plausible mechanistic pathway and the fluorescence enhancement of IHP with Zn2+ ions were highly gauged by density functional theoretical (DFT) calculations. Moreover, the probe IHP has been successfully employed for monitoring Zn2+ ion in HeLa cells and live cell imaging analysis in Zebrafish embryos.

Supramolecular Energetic and Topological Study of Halogenated Aryl Carboxylic Acids

A supramolecular energetic and topological study of 12 monohalogenated aryl carboxylic acids (F, Cl, Br, I) in the ortho, meta, and para positions was performed. The energy of intermolecular interactions was determined from long-range corrected hybrid density functional theoretical computational calculations, using the ωB97X-D3 method. The surface of contact between the molecules and the molecular coordination numbers were determined. From these data, all intermolecular interactions were classified, and the robustness of the interactions was evaluated. Thus, the molecule (Mn) allocations around a central molecule (M1) are proposed. In addition, the energy from the intermolecular interactions present in the first coordination sphere, which involves the central molecule, the energy resulting from the interactions between the peripheral molecules and the total energy of the cluster provided by all interactions, was determined. The role of hydrogen bonding (O–H···O, C–H···O, and C–H···X), π···π interactions, and halogen bonding (X···X) were evaluated, in the formation of the first coordination sphere and in the nucleation process.

Highly efficient detection of Cu2+ and B4 O7 2- based on a recyclable asymmetric salamo-based probe in aqueous medium.

An asymmetric salamo-based probe molecule (H2 L) was synthesized and characterized structurally. When DMF/H2 O (9:1) was used as the solvent, it was shown probe H2 L has high sensitivity to Cu2+ . Using high-resolution mass spectrometry and theoretical calculation, it was found that probe H2 L could form a more stable complex (1:1) with Cu2+ , the minimum limit of detection (LOD) of H2 L for Cu2+ was calculated as 9.95 × 10-8 M. In addition, probe H2 L could also be used to identify B4 O7 2- under the same detection conditions and the minimum LOD of H2 L for B4 O7 2- was calculated as 4.98 × 10-7 M. At the same time, density functional theory theoretical calculation further proved the flexibility of probe H2 L. Through the action of EDTA, probe H2 L had a cyclic ability to recognize Cu2+ , and showed a better response in the physiological pH range; probe H2 L had the characteristics of fast recognition speed and high efficiency. In addition, with probe H2 L test paper for Cu2+ and B4 O7 2- , the effect was more obvious. Meanwhile, probe H2 L can be used to quantitatively detect Cu2+ in water samples.

Near-infrared phosphorescence emission of three-fold interpenetrated MOF based on 1,4-bis(imidazole-1-ylmethyl)benzene: Syntheses, structure and photoelectron performance

One new Zn(II) based 3D metal-organic framework (MOF) [Zn(IPA) (TBMIM)] (1) (IPA ​= ​isophthalic acid, TBMIM ​= ​1,4-bis(imidazole-1-ylmethyl)benzene) has been synthesized under hydrothermal conditions. X-ray single-crystal diffraction analysis indicates that the title MOF exhibits a 3-fold interpenetrated diamond network with new type of molecular braid. Time-resolved measurements reveal that 1 emissions rare example of near-infrared phosphorescence at room temperature. The density functional theoretical (DFT) calculations indicate complete separation of molecular orbits between IPA and TBMIM ligands, which is in favor of the generation of triplet state excitons. This MOF also shows well photoelectron responds performance owing to the abundant π···π stacking in the entanglement molecular braids, which afford long-range π electrons delocalization for efficient electron transport.

Theoretical Study on the Structural-Function Relationship of Manganese(III)-Iodosylarene Adducts

Metal-iodosylarene complexes have been recently viewed as a second oxidant alongside of the well-known high-valent metal-oxo species. Extensive efforts have been exerted to unveil the structure-function relationship of various metal-iodosylarene complexes. In the present manuscript, density functional theoretical calculations were employed to investigate such relationship of a specific manganese-iodosylbenzene complex [MnIII(TBDAP)(PhIO)(OH)]2+ (1). Our results fit the experimental observations and revealed new mechanistic findings. 1 acts as a stepwise 1e+1e oxidant in sulfoxidation reactions. Surprisingly, C-H bond activation of 9,10-dihydroanthracene (DHA) by 1 proceeds via a novel ionic hydride transfer/proton transfer (HT/PT) mechanism. As a comparison to 1, the electrophilicity of an iodosylbenzene monomer PhIO was investigated. PhIO performs concerted 2e-oxidations both in sulfoxidation and C-H activation. Hydroxylation of DHA by PhIO was found to proceed via a novel ionic and concerted proton-transfer/hydroxyl-rebound mechanism involving 2e-oxidation to form a transient carbonium species.

Hyperfine field studies of the high-pressure phase of noncentrosymmetric superconductor RhGe (B20) doped with hafnium

We have used the time differential perturbed angular correlation (TDPAC) spectroscopy to measure the electric and magnetic hyperfine fields in RhGe crystallized in the B20 cubic lattice structure and weakly doped with Hf (0.5–2 atomic %) in the temperature range from 5 K to 295 K. Two most commonly used nuclei probes, 111In→111Cd and 181Hf→181Ta, have been used. The experimental results combined with theoretical density functional calculations indicate that the In/Cd impurities substitute into the Ge-site whereas the Ta/Hf probes substitute into the Rh-site. It has also been found that the Ta/Hf impurity strongly distorts the local crystal environment, whereas the effect from the In/Cd probe is weak. There are no reliable evidences of the magnetic order in the studied alloys at low temperatures.

Experimental and theoretical (DFT) investigation of crystallographic, spectroscopic and Hirshfeld surface analysis of anilinium arsenate

In the present communication, aniline with arsenic acid molecular complex has been taken as the subject for experimental and theoretical investigation. The anilinium arsenate (ANILAS) – a new crystalline product is grown by slow evaporation technique at room temperature. Density functional theoretical calculations have been computed with Gaussian 09 program. The structure is optimized with DFT/B3LYP-6–311G(d,p) basis set. The vibrational frequencies and electronic properties have been done with the help of Density Functional Theory (DFT) computations. The charge transfer, as well as occurrence of strong inter and intra molecular interactions were confirmed by frontier molecular orbital analysis, natural bonding orbital analysis (NBO) and molecular electrostatic potential. 1H and 13C NMR chemical shift of the studied compound has also been calculated using Gauge Independent Atomic Orbital (GIAO) method. Further, "the 3D Hirshfeld surface analysis and 2D fingerprint maps gives deep insight into the intermolecular interactions between the compound".

Experimental and theoretical insight into the extraction mechanism, kinetics, thermodynamics, complexation and radiolytic stability of novel calix crown ether in ionic liquid with Sr2+

A comparative evaluation was carried out for the extraction of Sr2+ using novel calix crown ether in molecular diluent and in ionic liquid. Though the trend in extraction profiles was found to be similar for both the systems, still, almost 5 times higher distribution ratio (D) values were observed in ionic liquid. The speciation studies revealed that; neutral Sr (NO3)2. DHCC species was formed in dodecane and the extraction followed through ‘solvation’ mechanism. However, ionic liquid medium (IL), anionic species, [Sr(NO3)3. DHCC]− was found to be predominating indicating ‘anion exchange’ mechanism. The slower kinetics of extraction in IL was attributed to the high viscosity of IL. The extraction process was found to be spontaneous, endothermic and entropy driven.IL based system was found to be radiolytically more stable compared to the molecular diluent (Mol dil) based system. The electron paramagnetic resonance (EPR) spectroscopic investigation revealed the formation of oxygen centered radical with orthorhombic symmetry (gx = 2.00105, gy = 2.00475, gz = 2.00835) in irradiated ligand. The density functional theoretical (DFT) calculation was utilized to investigate the complexation and speciation in detail in microscopic level.

Impact of oxygen vacancy occupancy on piezo-catalytic activity of BaTiO3 nanobelt

BaTiO3 nanobelt featuring controlled oxygen vacancies, namely BTO-OV-X (X represents time (h) of vacuum heat-treatment), were prepared to systematically investigate the effect of oxygen vacancies occupancy on pizeocatalytic performance for degradation of organic pollutant. Remarkably, the creation of oxygen vacancies on BaTiO3 can mediate the piezocatalytic activity. The piezocatalytic activity exhibited a volcano-type trend with increasing oxygen vacancies. Results from first-principles density functional theoretical (DFT) calculations and O2-temperature programmed desorption (O2-TPD) measurement indicated that the presence of oxygen vacancies could efficiently adsorb and activate O2 on the surface of BaTiO3 nanobelt and consequently enhance piezocatalytic activity. Importantly, with the aid of piezoresponse force microscopy (PFM) measurement, the intrinsic reason of volcano-type trend of oxygen vacancy-activity was well unveiled. This work reveals the effect and mechanism of oxygen vacancy occupancy on enhancing piezocatalytic activity of BaTiO3 nanobelt and will shed light on design of efficient piezocatalysts in the future.

A Chemodosimetric Approach for Fluorimetric Detection of Hg2+ Ions by Trinuclear Zn(II)/Cd(II) Schiff Base Complex: First Case of Intermediate Trapping in a Chemodosimetric Approach.

The present work discloses the application of two fluorescent zinc and cadmium complexes (1 and 2) for sensing of Hg(II) ions through a chemodosimetric approach. The ligand under consideration in this work is a N2O donor Schiff base ligand (E)-4-bromo-2-(((2-morpholinoethyl)imino)methyl)phenol (HL), which has been harnessed to generate complexes [Zn3L2(OAc)4] (1) and [Cd3L2(OAc)4] (2). X-ray single crystal diffraction studies unveil the trinuclear skeleton of complexes 1 and 2. Both complexes have been found to be highly fluorescent in nature. However, the quantum efficiency of Zn(II) complex (1) dominates over the Cd(II) analogue (2). The absorption and emission spectroscopic properties of the complexes have been investigated by density functional theory. Complexes 1 and 2 can detect Hg2+ ions selectively by fluorescence quenching, and it is noteworthy to mention that the mechanism of sensing is unique as well as interesting. In the presence of Hg2+ ions, complexes 1 and 2 are transformed to mononuclear mercuric intermediate complex (3) and finally to a trinuclear mercuric complex (4) by hydrolysis. We have successfully trapped the intermediate complex 3, and we characterized it with the aid of X-ray crystallography. Transformation of complexes 1 and 2 to intermediate complex 3 and finally to 4 has been established by UV-vis spectroscopy, fluorescence spectroscopy, ESI-MS spectroscopy, 1H NMR spectroscopy, and X-ray crystallography. The spontaneity of the above conversion is well supported by thermodynamic aspects as reflected from density functional theoretical calculations.

Selective Metal-Ligand Bond-Breaking Driven by Weak Intermolecular Interactions: From Metamagnetic Mn(III)-Monomer to Hexacyanoferrate(II)-Bridged Metamagnetic Mn2Fe Trimer.

Metal-ligand coordination interactions are usually much stronger than weak intermolecular interactions. Nevertheless, here, we show experimental evidence and theoretical confirmation of a very rare example where metal-ligand bonds dissociate in an irreversible way, helped by a large number of weak intermolecular interactions that surpass the energy of the metal-ligand bond. Thus, we describe the design and synthesis of trinuclear Mn2Fe complex {[Mn(L)(H2O)]2Fe(CN)6},2- starting from a mononuclear Mn(III)-Schiff base complex: [Mn(L)(H2O)Cl] (1) and [Fe(CN)6]4- anions. This reaction implies the dissociation of Mn(III)-Cl coordination bonds and the formation of Mn(III)-NC bonds with the help of several intermolecular interactions. Here, we present the synthesis, crystal structure, and magnetic characterization of the monomeric Mn(III) complex [Mn(L)(H2O)Cl] (1) and of compound (H3O)[Mn(L)(H2O)2]{[Mn(L)(H2O)]2Fe(CN)6}·4H2O (2) (H2L = 2,2'-((1E,1'E)-(ethane-1,2-diylbis(azaneylylidene))bis(methaneylylidene))bis(4-methoxyphenol)). Complex 1 is a monomer where the Schiff base ligand (L) is coordinated to the four equatorial positions of the Mn(III) center with a H2O molecule and a Cl- ion at the axial sites and the monomeric units are assembled by π-π and hydrogen-bonding interactions to build supramolecular dimers. The combination of [Fe(CN)6]4- with complex 1 leads to the formation of linear Mn-NC-Fe-CN-Mn trimers where two trans cyano groups of the [Fe(CN)6]4- anion replace the labile chloride from the coordination sphere of two [Mn(L)(H2O)Cl] complexes, giving rise to the linear anionic {[Mn(L)(H2O)]2Fe(CN)6}2- trimer. This Mn2Fe trimer crystallizes with an oxonium cation and a mononuclear [Mn(L)(H2O)2]+ cation, closely related to the precursor neutral complex [Mn(L)(H2O)Cl]. In compound 2, the Mn2Fe trimers are assembled by several hydrogen-bonding and π-π interactions to frame an extended structure similar to that of complex 1. Density functional theoretical (DFT) calculations at the PBE1PBE-D3/def2-TZVP level show that the bond dissociation energy (-29.3 kcal/mol) for the Mn(III)-Cl bond is smaller than the summation of all the weak intermolecular interactions (-30.1 kcal/mol). Variable-temperature magnetic studies imply the existence of weak intermolecular antiferromagnetic couplings in both compounds, which can be can cancelled with a critical field of ca. 2.0 and 2.5 T at 2 K for compounds 1 and 2, respectively. The magnetic properties of compound 1 have been fit with a simple S = 2 monomer with g = 1.959, a weak zero-field splitting (|D| = 1.23 cm-1), and a very weak intermolecular interaction (zJ = -0.03 cm-1). For compound 2, we have used a model with an S = 2 monomer with ZFS plus an S = 2 antiferromagnetically coupled dimer with g = 2.009, |D| = 1.21 cm-1, and J = -0.42 cm-1. The metamagnetic behavior of both compounds is attributed to the weak intermolecular π-π and hydrogen-bonding interactions.

Revealing the optoelectronic properties of Re-based double perovskites using the Tran-Blaha modified Becke-Johnson with density functional theory.

Density functional theoretical (DFT) calculations were carried out to explore the electronic and optical properties of double ordered Ba2NaReO6, Ba2LiReO6, and Sr2LiReO6 perovskites by employing the state-of-the-art exchange-correlation potential, i.e., Tran-Blaha modified Becke-Johnson for the electronic system. The calculated electronic band structures show an indirect band gap along with a semiconductor nature. Total and partial densities of state peaks were analyzed in light of effective contributions of various electronic states. The significant optical parameters, including the components of dielectric constant, the energy loss function, the absorption coefficient, the reflectivity spectra, the refractive index, and the extinction coefficient, were computed and discussed in details for radiation up to 14eV. Finally, we studied the inter-band contributions from the optical characteristics. Our present study might be considered as first theoretical quantitative calculations of the optical and electronic behavior in the cubic phase of double perovskite materials based on rhenium.

Phonon dispersion, Raman spectra, and evidence for spin-phonon coupling in MnV2O4 from first principles

MnV$_2$O$_4$ in the spinel structure is known to exhibit coupled orbital and spin ordering, and its Raman spectra show interesting anomalies in its low-temperature phase. With a goal to explain this behavior involving coupled spins and phonons, we determine here the spin-phonon couplings in MnV$_2$O$_4$ from a theoretical analysis of its phonon spectra and their dependence on spin-ordering and electron correlations, obtained from first-principles density functional theoretical calculations. Using these in an analysis based on a Landau-like theory, we uncover the mechanism governing the Raman anomalies observed in its low-temperature phase.

Rational construction of heterostructured core-shell Bi2S3@Co9S8 complex hollow particles toward high-performance Li- and Na-ion storage

The development of hollow structures with structural and composition complexity are highly attractive in the field of energy storage. In the present work, we demonstrate the rational construction of unique heterostructured core-shell Bi2S3@Co9S8 complex hollow particles (CHPs) through a facile metal-organic framework (MOF)-engaged strategy, in which the Bi2S3 spheres are well confined in the Co9S8 multi-cavity hollow shells. Benefiting from the specific structural and composition advantages, the core-shell Bi2S3@Co9S8 CHPs exhibit remarkable Li- and Na-ion storage performance in the aspects of high reversible capacity, excellent rate performance and long-term cycling stability. Electrochemical analyses reveal fast reaction kinetics in the core-shell Bi2S3@Co9S8 CHPs. Meanwhile, a Bi2S3@Co9S8//LiFePO4 full cell is successfully fabricated to evaluate their potential for real applications. In addition, the possible reaction mechanisms of the core-shell Bi2S3@Co9S8 CHPs for both Li- and Na-ion storage have been investigated via ex situ X-ray diffraction technique. Furthermore, density functional theoretical calculations confirm the heterostructure in the Bi2S3@Co9S8 CHPs can enhance the electrical conductivity and reaction kinetics. This work may offer new opportunities for integration of two active anode materials with high capacity and electrochemical activity into one heterostructured complex hollow structure.

Facile formation of tetragonal-Nb2O5 microspheres for high-rate and stable lithium storage with high areal capacity

Niobium pentoxide (Nb2O5) has attracted great attention as an anode for lithium-ion battery, which is attributed to the high-rate and good stability performances. In this work, TT-, T-, M-, and H-Nb2O5 microspheres were synthesized by a facile one-step thermal oxidation method. Ion and electron transport properties of Nb2O5 with different phases were investigated by both electrochemical analyses and density functional theoretical calculations. Without nanostructuring and carbon modification, the tetragonal Nb2O5 (M-Nb2O5) displays preferable rate capability (121 mAh g−1 at 5 A g−1), enhanced reversible capacity (163 mAh g−1 at 0.2 A g−1) and better cycling stability (82.3% capacity retention after 1000 cycles) when compared with TT-, T-, and H-Nb2O5. Electrochemical analyses further reveal the diffusion-controlled Li+ intercalation kinetics and in-situ X-ray diffraction analysis indicates superior structural stability upon Li+ intercalation/deintercalation. Benefiting from the intrinsic fast ion/electron transport, a high areal capacity of 2.24 mAh cm−2 is obtained even at an ultrahigh mass loading of 22.51 mg cm−2. This work can promote the development of Nb2O5 materials for high areal capacity and stable lithium storage towards practical applications.

Sandwich-like dual carbon layers coated NiO hollow spheres with superior lithium storage performances

Transition metal oxides (e.g. NiO) have been considered as promising high-capacity anode in lithium ion batteries (LIBs). However, the low electronic conductivity and huge volume change during cycling lead to rapid capacity fading and poor rate capability. To solve those drawbacks, we design a sandwich-like dual carbon layers coated hollow structured NiO (C@NiO@NC). The NiO nanosheets are anchored on the surface of hollow carbon nanospheres and then coated with N-doped porous carbon layer, which confine them between two carbon shells. Such hierarchical architecture with high surface area increases the contact between the electrode and electrolyte, resulting in decreased Li+ diffusion pathway. Moreover, the dual carbon layers enhance the electronic conductivity of C@NiO@NC and effectively buffer the volume changes of NiO during cycling. Therefore, this sample delivers a high capacity (1189 mA h g−1 at 100 mA g−1), superior rate capability (420 mA h g−1 at ultrahigh rate of 10000 mA g−1) and outstanding cycling stability (96.1% at 1000 mA g−1 after 1000 cycles) when used as LIBs anode. The density functional theoretical calculation further proves the enhanced electronic conductivity and more energetic favorable capability of C@NiO@NC. This facile method can be extended to other transition-metal oxides with superior electrochemical performance.

Low-temperature properties of pyrochlore Lu2Ir2O7

Low-temperature properties of Lu2Ir2O7 were studied by means of magnetization, ac-susceptibility and specific heat measurements. Our low-temperature measurements reveal a bifurcation of ZFC and FC magnetization data below 140 K, which is further pronounced as a broad anomaly in the temperature development of specific heat and ac-susceptibility. The anomaly can be attributed to the same physical mechanism as discussed for other A2Ir2O7 with A = magnetic rare-earth element, i.e. to short-range correlations among Ir4+ magnetic moments, rather than to a long-range order of Ir sublattice reported earlier. The ac-susceptibility data revealed a strong frequency dependence of the signal, a paradigmatic sign of a spin-glass transition. The analysis of low-temperature specific heat data brought important information on physical properties of Lu2Ir2O7, in striking agreement with our density functional theoretical (DFT) calculations, concluding relatively weak electron-phonon interaction and semimetallic ground state in Lu2Ir2O7.

Combined Experimental and Density Functional Theoretical Studies of Am3+ and Eu3+ Extraction and Complexation with Different Nitrilotriacetamide (NTA) Derivatives

AbstractN,N,N′,N′,N“,N”‐hexaalkylnitrilotriacetoamide (HRNTA) derivatives were found to be promising for the separation of trivalent actinides from lanthanides, which is a burning topic in the back end of the nuclear fuel cycle. In the present work, separation of Am3+ from Eu3+ was studied using the N,N,N’,N’,N’’,N’’‐hexa‐2‐ethylhexylnitrilotriacetamide (H2EHNTA) derivative and the role of the diluent medium to control the extractable complex was demonstrated. The effect of alkyl chain length and branching in the alkyl chain of different HRNTA (R=methyl, n‐butyl, n‐hexyl, n‐dodecyl and 2‐ethylhexyl) derivatives on their complexation with Eu3+ were investigated using steady‐state and time‐resolved luminescence studies. Different species formed at different ligand to metal ratios were identified from the luminescence titration experiments and their lifetime values measured. The experimental results were corroborated with the help of density functional theoretical (DFT) calculations on Am3+ and Eu3+ complexes of HRNTA derivatives with varying alkyl chain length and branching.

Synthesis of 2, 5‐Diamino‐p—benzoquinones via Aerobic Oxidative C(sp2)‐C(sp2) Bond Cleavage and Mechanistic Studies

AbstractA facile synthesis of 2, 5‐diamino‐p‐benzoquinones (DABQs) is reported under very mild conditions by mere crystallization. Mechanistic studies by density functional theoretical (DFT) calculations revealed an oxidative C(sp2)‐C(sp2) bond cleavage reaction mechanism via a dioxetane intermediate, from enamine oxidation of a mixture of ethyl vanillin and primary amines by triplet molecular oxygen. A second air oxidation event in the sequence of the reaction that results in C(sp2)‐C(sp2) bond formation is also described by DFT studies. The mechanistic insights enabled synthesis of both symmetric and unsymmetric DABQs from primary amines with a broad substrate scope.

Unveiling the binding interaction of zinc (II) complexes of homologous Schiff‐base ligands on the surface of BSA protein: A combined experimental and theoretical approach

Four new zinc (II) complexes [Zn (HL1H)Br2] (1), [Zn (HL1H)Cl2] (2), [Zn2(HL2)Br3] (3), and [Zn (HL2)Cl] (4) have been synthesized by adopting template synthetic strategy and utilizing two homologous Schiff base ligands (H2L1 = 4‐bromo‐2‐{[2‐(2‐hydroxyethylamino)‐ethylimino]‐methyl}‐6‐methoxyphenol, H2L2 = 4‐bromo‐2‐{[3‐(2‐hydroxyethylamino)propylimino]methyl}‐6‐methoxyphenol), differing in one ‐CH2‐ unit in the ligating backbone, by adopting template synthetic strategy. All the complexes have been characterized by single crystal X‐ray diffraction analysis as well as by other routine physicochemical techniques. Ligand mediated structural variations have been observed and rationalized by density functional theoretical (DFT) calculations. Interaction of the complexes 1–4 with Bovine Serum Albumin protein (BSA) has been studied by different spectroscopic techniques. A complete thermodynamic profile (ΔHo, ΔSo and ΔGo) was evaluated initially from the change in absorption and fluorescence spectra upon addition of BSA to the complexes. Appreciable binding constant values in the range ~ 0.94–4.51 × 104 M−1 indicate efficient binding tendency of the complexes to BSA with the sequence 1 ≅ 2 > 3 ≅ 4. Circular dichroism (CD), isothermal calorimetric titration experiments, molecular docking and molecular dynamics have been performed to gain deep insight into the binding regions of complex 1 to BSA. Experimental evidences suggest an interaction of zinc complexes at the surface of BSA protein and this particular binding has been exploited to determine unknown concentration of BSA protein. For this purpose complex 1 was explored as a BSA protein quantification tool.