Theoretical and experimental investigation of NMR, IR and UV-Visible spectra of hydroxyl-substituted 4-chloromethylcoumarin derivatives

Abstract

UV-Visible, FTIR and NMR experimental and theoretical spectral results have been compared for five substituted-4-chloromethylcoumarin derivatives (6-OH, 7-OH, 6,7-di-OH, 7,8-di-OH and 5,7-di-OH-substituted-4-chloromethylcoumarins). The theoretical investigation was conducted using density functional theory (DFT), namely the M06-2X functional form with 6-311+G(2df,2p) basis set. The 13 C-NMR and 1 H-NMR chemical shifts, vibrational spectra and molecular orbitals of the excited states were calculated based on their optimized geometries. The calculated values were found to have close agreement with the experimental values. The theoretical data are useful and could be important in the proper selection of compounds as intermediates for different chemical applications and modifications.

Visible-to-NIR-Light Activated Release: From Small Molecules to Nanomaterials

“…293 Because of its extended D−π−A backbone, 267 35c exhibited a much stronger 2P absorption than 30c (309 vs 2.3 GM at 800 nm) and a ∼2-fold higher 2P uncaging cross section (δ unc = 0.26 vs 0.12 GM at 800 nm). 293 Coumarin derivatives bearing EDGs at the 6-position exhibited greater bathochromic shifts in absorption than their 7-EDG counterparts, 278,290,405,406 but usually also exhibited less efficient photorelease (Table 8). 278,290 For example, the (6-methoxycoumarin-4-yl)methyl compound 39a had a 20 nm bathochromic shift of λ max abs relative to its 7-methoxy analog 29b and was photolyzed to release cAMP as an LG ∼4-times less efficiently.…”

“…Coumarin derivatives bearing EDGs at the 6-position exhibited greater bathochromic shifts in absorption than their 7-EDG counterparts, ,,, but usually also exhibited less efficient photorelease (Table ). , For example, the (6-methoxy­coumarin-4-yl)­methyl compound 39a had a 20 nm bathochromic shift of λ max abs relative to its 7-methoxy analog 29b and was photolyzed to release cAMP as an LG ∼4-times less efficiently. , The spectroscopic and photochemical properties of the 6,7-dialkoxy derivatives 39b – d resembled those of their 6- or 7-monosubstituted analogs.…”

Isofraxidin: Synthesis, Biosynthesis, Isolation, Pharmacokinetic and Pharmacological Properties

“…Nowadays, spectroscopic methods including UV-spectroscopy, infrared (IR), nuclear magnetic resonance ( 1 H NMR, 13 C NMR), and mass spectroscopy are used for identification and structure elucidation of natural compounds such as coumarins. Melting point, type, and color of compound crystals are also of the other indicators [ 86 , 87 ]. Heterocyclic molecules such as coumarins have a combination of electronic transitions between π-π* and n -π* that is related to the presence of α-pyrone and benzene rings, as well as the carbonyl group.…”