Synthesis, spectroscopic investigation and computational study of 3-(1-(((methoxycarbonyl)oxy)imino)ethyl)-2H-chromen-2-one

Exploration of nonlinear optical properties of 4-methyl-4H-1,2,4-triazol-3-yl)thio)-N-phenylpropanamide based derivatives: experimental and DFT approach

Triazoles, nitrogen-containing heterocycles, have gained attention for their applications in medicinal chemistry, drug discovery, agrochemicals, and material sciences. In the current study, we synthesized novel derivatives of N-substituted 2-((5-(3-bromophenyl)-4-methyl-4H-1,2,4-triazol-3-yl)thio)-N-phenylpropanamide and conducted a comprehensive investigation using density functional theory (DFT). These novel structural hybrids of 1,2,4-triazole were synthesized through the multi-step chemical modifications of 3-bromobenzoic acid (1). Initially, compound 1 was converted into its methyl-3-bromobenzoate (2) which was then transformed into 3-bromobenzohydrazide (3). The final step involved the cyclization of compound 3, producing its 1,2,4-triazole derivative (4). This intermediate was then coupled with different electrophiles, resulting in the formation of the final derivatives (7a-7c). Additionally, the characterization of these triazole-based compounds (7a, 7b, and 7c) were carried out using techniques such as IR, HNMR, and UV-visible spectroscopy to understand their structural and spectroscopic properties. The DFT study utilized M06/6-311G(d,p) functional to investigate geometrical parameters, HOMO-LUMO energies, natural bond orbital analyses, transition density matrix (TDM), density of states, and nonlinear optical (NLO) properties. The FMO analysis revealed that compound 7c exhibited the lowest band gap value (4.618 eV). Notably, compound 7c exhibited significant linear polarizability (4.195 >  × 10-23) and first and second hyperpolarizabilities (6.317 >  × 10-30, 4.314 × 10-35), signifying its potential for nonlinear optical applications. These NLO characteristics imply that each of our compounds, especially 7c, plays a crucial part in fabricating materials showing promising NLO properties for optoelectronic applications.

Heterocyclic Donor Moiety Effect on Optical Nonlinearity Behavior of Chrysene-Based Chromophores with Push-Pull Configuration via the Quantum Chemical Approach

Organic-based nonlinear optical (NLO) materials may be used in many optical-electronic systems and other next-generation defense technologies. With the importance of NLO materials, a series of push-pull architecture (D-π-A) derivatives (DTMD2-DTMD6) were devised from DTMR1 through structural alteration of different efficient donor heterocyclic groups. Density functional theory-based computations were executed at the MPW1PW91/6-31G(d,p) level to explore the NLO behavior of the derivatives. To investigate the optoelectronic behavior of the said compounds, various analyses like the frontier molecular orbital (FMO), global reactivity parameters, density of state (DOS), absorption spectra (UV-vis), natural bond orbital, and transition density matrix (TDM) were performed. The derivatives have a smaller band gap (2.156-1.492 eV) and a larger bathochromic shift (λmax = 692.838-969.605 nm) as compared to the reference chromophore (ΔE = 2.306 eV and λmax = 677.949 nm). FMO analysis revealed substantial charge conduction out of the donor toward the acceptor via a spacer that was also shown by TDM and DOS analyses. All derivatives showed promising NLO results, with the maximum amplitude of linear polarizability ⟨α⟩ and first (βtotal) and second (γtotal) hyperpolarizabilities over their reference chromophore. DTMD2 contained the highest βtotal (7.220 × 10-27 esu) and γtotal (1.720 × 10-31 esu) values corresponding with the reduced band gap (1.492 eV), representing potential futures for a large NLO amplitude. This structural modification through the use of various donors has played a significant part in achieving promising NLO behavior in the modified compounds.

Synthesis, Characterizations, Hirshfeld Surface Analysis, DFT, and NLO Study of a Schiff Base Derived from Trifluoromethyl Amine

We synthesized an imine-based (Schiff base) crystalline organic chromophore, i.e., (E)-2-ethoxy-6-(((3-(trifluoromethyl)phenyl)imino)methyl)phenol (ETPMP), and explored its nonlinear optical (NLO) properties. The crystalline structure of ETPMP was determined by the XRD technique and equated with the associated structures utilizing a Cambridge Structural Database search. The supramolecular assembly of ETPMP was investigated regarding intermolecular interactions and short contacts by Hirshfeld surface analysis. Void analysis was performed to check the mechanical response of the crystal. Supramolecular assembly was further inspected by interaction energy calculations that were performed with the B3LYP/6-31G(d,p) functional. Besides this, the NLO properties of ETPMP and other already reported crystal TFMOS were explored utilizing the M06/6-31G(d,p) functional of the DFT approach. An excellent agreement was observed between XRD and DFT results of geometric parameters of the above-mentioned crystals. Narrow band gap along with bathochromic shift (3.489 eV and 317.225 nm, respectively) were investigated in TFMOS than that of ETPMP. Owing to these unique properties, TFMOS possesses higher linear (⟨a⟩ = 3.835 × 10-23 esu) and nonlinear (γtot. = 1.346 × 10-34 esu) response as compared to ETPMP. The outcomes explicitly show the higher nonlinearity in TFMOS, highlighting its importance in potential NLO applications.

Role of donors in triggering second order non-linear optical properties of non-fullerene FCO-2FR1 based derivatives: A theoretical perspective

The organic compounds are known as an emerging class in the field of nonlinear optical (NLO) materials. In this paper, D-π-A configured oxygen containing organic chromophores (FD2-FD6) were designed by incorporating various donors in the chemical structure of FCO-2FR1. This work is also inspired by the feasibility of FCO-2FR1 as an efficient solar cell. Theoretical approach involving DFT functional i.e., B3LYP/6-311G(d,p) was utilized to achieve useful information regarding their electronic, structural, chemical and photonic properties. The structural modifications revealed significant electronic contribution in designing HOMOs and LUMOs for the derivatives with lowered energy gaps. The lowest HOMO-LUMO band gap obtained was 1.223 eV for FD2 compound in comparison to the reference molecule (FCO-2FR1) i.e., 2.053 eV. Moreover, the DFT findings revealed that the end-capped substituents play a key role in enhancing the NLO response of these push-pull chromophores. The UV-Vis spectra of tailored molecules revealed larger λ _max values than the reference compound. Furthermore, strong intramolecular interactions showed the highest stabilization energy (28.40 kcal mol^-1) for FD2 in the natural bond orbitals (NBOs) transitions, combined with the least binding energy (-0.432 eV). Successfully, the NLO results were favorable for the same chromophore (FD2) which showed the highest value for dipole moment (μ _tot = 20.049 D) and first hyper-polarizability (β _tot = 11.22 × 10^-27 esu). Similarly, the largest value for linear polarizability ⟨α⟩ was obtained as 2.936 × 10^-22 esu for FD3 compound. Overall, the designed compounds were calculated with greater NLO values as compared to FCO-2FR1. The current study may provoke the researchers towards designing of highly efficient NLO materials via using the suitable organic linking species.

Influence of End-Capped Modifications in the Nonlinear Optical Amplitude of Nonfullerene-Based Chromophores with a D-π-A Architecture: A DFT/TDDFT Study

Nonlinear optical (NLO) materials have several uses in many fields such as solid physics, biology, medicine, nuclear physics, and material research. Therefore, a series of nonfullerene-based derivatives (CC10D1-CC10D8) with a D-π-A configuration was planned for the NLO investigation using CC10R as the reference molecule with structural alternations at acceptor moieties. Natural bonding orbital (NBO), UV-vis spectra, frontier molecular orbitals (FMOs), global reactivity parameters (GRPs), transition density matrix (TDM), and density of states (DOS) were analyzed using the M06/6-311G(d,p) functional in chloroform solvent to understand the NLO responses of CC10R and CC10D1-CC10D8. The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) band gaps of CC10D1-CC10D6 were illustrated to be lower than that of CC10R, with the larger bathochromic shift (726.408-782.674 nm) resulting in a significant NLO response. Along with the band gap, the FMO method also identified an efficient interfacial charge transfer from D to A moieties via a π-bridge, which was further supported by the DOS and TDM map. Moreover, NBO calculations demonstrated that extended hyperconjugation and strong internal molecular interactions were important in their stabilization. The dipole moment (μ), linear polarizability ⟨α⟩, hyperpolarizability (β_total), and second-order hyperpolarizability (γ_total.) were studied for CC10R and CC10D1-CC10D8. Among all of the derivatives, CC10D2 was proven to be the most appropriate candidate because of its suitable NLO behavior such as being well-supported by a reduced band gap (2.093 eV) and having a suitable maximum absorption wavelength (782.674 nm). Therefore, CC10D2 was reported to have a greater value of first hyperpolarizability (208 659.330 a.u.) compared with other derivatives and CC10R. For the second hyperpolarizability, a greater value was obtained for CC10R (5.855 × 10⁷ a.u.), and its derivatives showed results comparable to that of the parent chromophore for γ_total. This theoretical framework reveals that structural customization with different acceptor units plays a significant role in obtaining attractive NLO materials for optoelectronic applications.

Balancing the transesterification reactivity of isosorbide with diphenyl carbonate: preferential activation of exo-OH

Exo-OH on ISB has long been asserted as a highly reactive moiety compared with endo-OH. Herein, we report that the nucleophilic attack surmounts steric hindrance in rendering endo-OH more reactive than exo-OH in case of transesterification with DPC.

The synthesis of 3-ethyl-5-methyl-2,6-diarylpiperidin-4-on-1-ium picrates and their spectral, XRD and theoretical studies

This paper reports the synthesis of 3-ethyl-5-methyl-2,6-diarylpiperidin-4-on-1-ium picrates (1–3). The compounds were characterized by spectral techniques and theoretical methods.

Turn on macrocyclic chemosensor for Al3+ ion with facile synthesis and application in live cell imaging

An effort of a new Schiff base macrocyclic chemosensor, 1⁴‑methyl‑2,6,8,12,14,18‑hexaaza‑1,7,13(1,2),4,10,16(1,4)‑hexabenzenacyclooctadecaphane‑2,5,8,11,14,17‑hexaene (me1) and 1⁴,7⁴‑dimethyl‑2,6,8,12,14,18‑hexaaza‑1,7,13(1,2),4,10,16(1,4)‑hexabenzenacyclooctadecadecaphane‑2,5,8,11,14,17‑hexaene (dm2), which enables selective sensing of Al³⁺ in aqueous DMF were synthesized by a simplistic one-step condensation reaction of macrocyclic compounds. The probe me1 and dm2 characterized by elemental analysis, FT-IR, ¹H and ¹³C NMR, LC-MS spectral techniques. The compounds as mentioned above subjected to FE-SEM with EDS and elemental color mapping. On addition of Al³⁺, the fluorescent probe me1 and dm2 induces turn-on responses in both absorption and sensing spectra by a PET mechanism. The receptor me1 and dm2 serve highly selective, sensitive and turn-on detection of Al³⁺. Further, they did not interfere with other cations present in biological or environmental samples. The detection limit is found to be 3μM and 5μM. From the view of cytotoxic activity, the ability of these compounds me1 and dm2 to inhibit the growth of KB cell lines examined. The chelating functionality of compounds me1 and dm2 examined for their inhibitory properties of KB cell, live cell images. The compounds me1 and dm2 subjected to theoretical studies by DFT-B3LYP invoking the 6-31G level of theory. The energy of the HOMO and LUMO has been established.

Combined experimental and theoretical studies on molecular structures, spectroscopy of 4-(3-(2-amino-3,5-dibromophenyl)-1-(benzoyl)-4,5-dihydro-1H-pyrazol-5-yl)benzonitriles through NBO, FT-IR, HOMO-LUMO and NLO analyzes

The pyrazole compounds 4-(3-(2-amino-3,5-dibromophenyl)-1-(4-substitutedbenzoyl)-4,5-dihydro-1H-pyrazol-5-yl) benzonitriles (4–6) have been synthesized and characterized by elemental, IR, 1HNMR spectral methods. In addition, the synthesized compounds were subjected to density functional theory for further understanding of the molecular architecture and optoelectronic properties. The optimized geometric parameters were in support of the corresponding experimental values. The FT-IR spectra of 4–6 have been investigated extensively using DFT employing B3LYP/6-31G (d,p) level theory. The molecular electrostatic potential analysis has been utilized to identify reactive sites of title compounds. Natural bonding orbital analysis proved the inter- and intra-molecular delocalization and acceptor–donor interactions based on the second-order perturbation interactions. The calculated band gap energies revealed that charge transfer occurs within the molecule. The polarizability and hyperpolarizability were calculated which show that compounds posses nonlinear optical nature.

The effect of chalcogen substitution on the structure and spectroscopy of 4,7-dimethyl-2H-chromen-2-one/thione analogues

The structural and spectroscopic properties of the 1-benzopyran-2-one/thione moiety.