Metalloporphyrinyl-Phosphonates with Serrated Chain Structures: Exfoliation and NIR Photothermal Effect

Abstract

Near-infrared (NIR) photothermal materials have received significant attention due to their potential applications in photothermal therapy, diagnosis, and imaging. In this work, we constructed three mixed-ligand metal phosphonates, namely, Co­(Ni–H6TPPP)­(phen)­(H2O)2 (CoNi), Ni­(Ni–H6TPPP)­(phen)­(H2O)2 (NiNi), and Co­(Co–H6TPPP)­(phen)­(H2O)2 (CoCo), where H10TPPP is 5,10,15,20-tetrakis­(p-phenylphosphonic acid)-porphyrin and phen is 1,10-phenanthroline. These compounds are isostructural showing 1D serrated chain structures in which the porphyrin rings are stacked between the chains with π–π interactions. All displayed a broad absorption from the UV–vis to NIR (ca. 1500 nm) regions in the solid state. Interestingly, the chains in these compounds can be chemically exfoliated in water by adjusting the pH, forming interwoven nanostrands/nanosheets with thicknesses of one to several chains. The photothermal effect was observed for CoNi, NiNi, and CoCo in the solid state and in HEPES solution (pH = 7.4) upon 808 nm laser irradiation, among which CoCo showed the highest photothermal conversion efficiency. The important role of the cobalt­(II) ion in the porphyrin ring and phenylphosphonic unit in extending π-electron delocalization and enhancing the absorption in the NIR region in CoCo is revealed by theoretical calculations.

Highly Sensitive and Breathability Flexible Piezoresistive Pressure Sensor Based on Xylon

“…By converting external mechanical signals into electrical signals, pressure sensors act as a "port" between the real world and the virtual world. Generally, according to different sensing mechanisms, pressure sensors can be classified as piezoresistive, [5][6][7][8] capacitive, [9][10][11][12] piezoelectric [13,14] and triboelectric [15,16] types. Among them, piezoresistive pressure sensors are distinguished by their high sensing ability, low power consumption, and uncomplicated manufacturing process.…”

Highly pH-stable lanthanide MOFs: a tunable luminescence and ratiometric luminescent probe for sulfamethazine

“…Third, due to the strong coordination abilities of −PO 3 H 2 groups, metal phosphonates can show higher thermal and chemical stabilities than other types of MOFs. 50,51 Meanwhile, the introduction of a hydrophobic group (-F) is also conducive to the synthesis of Ln-MOFs with high water stability. In addition, the -COOH groups of the secondary ligand H 2 C 2 O 4 can occupy the residual coordination sites of Ln 3+ ions instead of the coordination sites of water molecules, which can simultaneously improve luminous efficiency and water stability.…”

Cu12-cluster-based metal–organic framework as a metastable intermediate in the formation of a layered copper phosphonate

“…Recently, near-infrared (NIR) photothermal materials based on MOFs or CPs have received increasing attention for their potential application in photothermal therapy, diagnosis, imaging, and others. 15–17 Cu II compounds are good candidates because they can absorb light in the NIR region due to d–d transition of the Cu II ion. 18 Fig.…”