1
|
Bejoymohandas KS, Redhu A, Sharma CH, SeethaLekshmi S, Divya IS, Kiran MSRN, Thalakulam M, Monti F, Nair RV, Varughese S. Polymorphism-driven Distinct Nanomechanical, Optical, Photophysical, and Conducting Properties in a Benzothiophene-quinoline. Chemistry 2024; 30:e202303558. [PMID: 38037264 DOI: 10.1002/chem.202303558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/30/2023] [Accepted: 11/30/2023] [Indexed: 12/02/2023]
Abstract
Polymorphic forms of organic conjugated small molecules, with their unique molecular shapes, packing arrangements, and interaction patterns, provide an excellent opportunity to uncover how their microstructures influence their observable properties. Ethyl-2-(1-benzothiophene-2-yl)quinoline-4-carboxylate (BZQ) exists as dimorphs with distinct crystal habits - blocks (BZB) and needles (BZN). The crystal forms differ in their molecular arrangements - BZB has a slip-stacked column-like structure in contrast to a zig-zag crystal packing with limited π-overlap in BZN. The BZB crystals characterized by extended π-stacking along [100] demonstrated semiconductor behavior, whereas the BZN, with its zig-zag crystal packing and limited stacking characteristics, was reckoned as an insulator. Monotropically related crystal forms also differ in their nanomechanical properties, with BZB crystals being considerably softer than BZN crystals. This discrepancy in mechanical behavior can be attributed to the distinct molecular arrangements adopted by each crystal form, resulting in unique mechanisms to relieve the strain generated during nanoindentation experiments. Waveguiding experiments on the acicular crystals of BZN revealed the passive waveguiding properties. Excitation of these crystals using a 532 nm laser confirmed the propagation of elastically scattered photons (green) and the subsequent generation of inelastically scattered (orange) photons by the crystals. Further, the dimorphs display dissimilar photoluminescence properties; they are both blue-emissive, but BZN displays twice the quantum yield of BZB. The study underscores the integral role of polymorphism in modulating the mechanical, photophysical, and conducting properties of functional molecular materials. Importantly, our findings reveal the existence of light-emitting crystal polymorphs with varying electric conductivity, a relatively scarce phenomenon in the literature.
Collapse
Affiliation(s)
- K S Bejoymohandas
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology Thiruvananthapuram, Kerala, 695019, India
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129, Bologna, Italy
| | - Ashish Redhu
- Department of Physics, Indian Institute of Technology Ropar, Punjab, 140001, India
| | - Chithra H Sharma
- School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala, 695551, India
| | - Sunil SeethaLekshmi
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology Thiruvananthapuram, Kerala, 695019, India
| | - I S Divya
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology Thiruvananthapuram, Kerala, 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - M S R N Kiran
- Department of Physics and Nanotechnology, SRM Institute of Science and Technology, Chennai, 603203, India
| | - Madhu Thalakulam
- School of Physics, Indian Institute of Science Education and Research Thiruvananthapuram, Kerala, 695551, India
| | - Filippo Monti
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129, Bologna, Italy
| | - Rajesh V Nair
- Department of Physics, Indian Institute of Technology Ropar, Punjab, 140001, India
| | - Sunil Varughese
- Chemical Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology Thiruvananthapuram, Kerala, 695019, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| |
Collapse
|
2
|
Reddy MLP, Bejoymohandas KS. Luminescent lanthanide-based molecular materials: applications in photodynamic therapy. Dalton Trans 2024; 53:1898-1914. [PMID: 38189418 DOI: 10.1039/d3dt04064j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Luminescent lanthanide molecular compounds have recently attracted attention as potential photosensitizers (PSs) for photodynamic therapy (PDT) against malignant cancer tumours because of their predictable systemic toxicity, temporospatial specificity, and minimal invasiveness. A photosensitizer exhibits no toxicity by itself, but in the presence of light and oxygen molecules, it can generate reactive oxygen species (ROS) to cause damage to proteins, nucleic acids, lipids, membranes, and organelles, which can induce cell apoptosis. This review focuses on the latest developments in luminescent lanthanide-based molecular materials as photosensitizers and their applications in photodynamic therapy. These molecular materials include lanthanide coordination complexes, nanoscale lanthanide coordination polymers, and lanthanide-based nanoscale metal-organic frameworks. In the end, the future challenges in the development of robust luminescent lanthanide molecular materials-based photosensitisers are outlined and emphasized to inspire the design of a new generation of phototheranostic agents.
Collapse
Affiliation(s)
- M L P Reddy
- CSIR-National Institute for Interdisciplinary Science & Technology (CSIR-NIIST), Thiruvananthapuram, 695 019, India.
| | - K S Bejoymohandas
- Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche (ISOF-CNR), Via Piero Gobetti 101, 40129 Bologna, Italy
| |
Collapse
|
3
|
Bejoymohandas KS, Kumar A, Sreenadh S, Varathan E, Varughese S, Subramanian V, Reddy MLP. A Highly Selective Chemosensor for Cyanide Derived from a Formyl-Functionalized Phosphorescent Iridium(III) Complex. Inorg Chem 2016; 55:3448-61. [PMID: 27008242 DOI: 10.1021/acs.inorgchem.5b02885] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A new phosphorescent iridium(III) complex, bis[2',6'-difluorophenyl-4-formylpyridinato-N,C4']iridium(III) (picolinate) (IrC), was synthesized, fully characterized by various spectroscopic techniques, and utilized for the detection of CN(-) on the basis of the widely known hypothesis of the formation of cyanohydrins. The solid-state structure of the developed IrC was authenticated by single-crystal X-ray diffraction. Notably, the iridium(III) complex exhibits intense red phosphorescence in the solid state at 298 K (ΦPL = 0.16) and faint emission in acetonitrile solution (ΦPL = 0.02). The cyanide anion binding properties with IrC in pure and aqueous acetonitrile solutions were systematically investigated using two different channels: i.e., by means of UV-vis absorption and photoluminescence. The addition of 2.0 equiv of cyanide to a solution of the iridium(III) complex in acetonitrile (c = 20 μM) visibly changes the color from orange to yellow. On the other hand, the PL intensity of IrC at 480 nm was dramatically enhanced ∼5.36 × 10(2)-fold within 100 s along with a strong signature of a blue shift of the emission by ∼155 nm with a detection limit of 2.16 × 10(-8) M. The cyanohydrin formation mechanism is further supported by results of a (1)H NMR titration of IrC with CN(-). As an integral part of this work, phosphorescent test strips have been constructed by impregnating Whatman filter paper with IrC for the trace detection of CN(-) in the contact mode, exhibiting a detection limit at the nanogram level (∼265 ng/mL). Finally, density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were performed to understand the electronic structure and the corresponding transitions involved in the designed phosphorescent iridium(III) complex probe and its cyanide adduct.
Collapse
Affiliation(s)
- K S Bejoymohandas
- Materials Science and Technology Division, CSIR-Network of Institutes for Solar Energy, CSIR-National Institute for Interdisciplinary Science & Technology (CSIR-NIIST) , Thiruvananthapuram 695 019, India.,Academy of Scientific and Innovative Research (AcSIR) , New Delhi 110025, India
| | - Ajay Kumar
- Materials Science and Technology Division, CSIR-Network of Institutes for Solar Energy, CSIR-National Institute for Interdisciplinary Science & Technology (CSIR-NIIST) , Thiruvananthapuram 695 019, India
| | - S Sreenadh
- Materials Science and Technology Division, CSIR-Network of Institutes for Solar Energy, CSIR-National Institute for Interdisciplinary Science & Technology (CSIR-NIIST) , Thiruvananthapuram 695 019, India
| | - E Varathan
- Chemical Laboratory, CSIR-Central Leather Research Institute , Chennai 600 020, India
| | - S Varughese
- Materials Science and Technology Division, CSIR-Network of Institutes for Solar Energy, CSIR-National Institute for Interdisciplinary Science & Technology (CSIR-NIIST) , Thiruvananthapuram 695 019, India
| | - V Subramanian
- Chemical Laboratory, CSIR-Central Leather Research Institute , Chennai 600 020, India
| | - M L P Reddy
- Materials Science and Technology Division, CSIR-Network of Institutes for Solar Energy, CSIR-National Institute for Interdisciplinary Science & Technology (CSIR-NIIST) , Thiruvananthapuram 695 019, India.,Academy of Scientific and Innovative Research (AcSIR) , New Delhi 110025, India
| |
Collapse
|
4
|
Das S, Bejoymohandas KS, Dey A, Biswas S, Reddy MLP, Morales R, Ruiz E, Titos-Padilla S, Colacio E, Chandrasekhar V. Amending the Anisotropy Barrier and Luminescence Behavior of Heterometallic Trinuclear Linear [MIILnIIIMII] (LnIII=Gd, Tb, Dy; MII=Mg/Zn) Complexes by Change from Divalent Paramagnetic to Diamagnetic Metal Ions. Chemistry 2015; 21:6449-64. [DOI: 10.1002/chem.201406666] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Indexed: 12/19/2022]
|