94953-74-9

Basic information

• Product Name: 4H-1-Benzopyran-4-one, 3,3'-dithiobis[2-phenyl-
• CAS NO: 94953-74-9
• Molecular Formula: C30H18O4S2
• Molecular Weight: 506.603
• Mol File: 94953-74-9.mol
• Article Data: 2

Chemical Properties

• CAS DataBase Reference: 4H-1-Benzopyran-4-one, 3,3'-dithiobis[2-phenyl-(CAS DataBase Reference)
• NIST Chemistry Reference: 4H-1-Benzopyran-4-one, 3,3'-dithiobis[2-phenyl-(94953-74-9)
• EPA Substance Registry System: 4H-1-Benzopyran-4-one, 3,3'-dithiobis[2-phenyl-(94953-74-9)

Safety Data

• Hazardous Substances Data: 94953-74-9(Hazardous Substances Data)

Upstream product

• 4010-33-7 2-acetylphenyl benzoate 
• 525-82-6 FLAVONE 
• 98-88-4 benzoyl chloride 
• 118-93-4 o-hydroxyacetophenone 
• 124-41-4 sodium methylate 
• 98153-13-0 3-Mercapto-2-phenyl-4H-1-benzopyran-4-one 
• 67139-31-5 trans-3-mesyloxyflavanone 
• 94953-61-4 Thioacetic acid S-((2R,3R)-4-oxo-2-phenyl-chroman-3-yl) ester 
• 94953-69-2 S-(4-oxo-2-phenyl-4H-chromen-3-yl) ethanethioate 

Downstream Products

• 98153-13-0 3-Mercapto-2-phenyl-4H-1-benzopyran-4-one 

Relevant articles and documents

Chapter Open for the Excited-State Intramolecular Thiol Proton Transfer in the Room-Temperature Solution

We report here, for the first time, the experimental observation on the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton in room-temperature solution. This phenomenon is demonstrated by a derivative of 3-thiolflavone (3TF), namely, 2-(4-(diethylamino)phenyl)-3-mercapto-4H-chromen-4-one (3NTF), which possesses an - S - H···O= intramolecular H-bond (denoted by the dashed line) and has an S1 absorption at 383 nm. Upon photoexcitation, 3NTF exhibits a distinctly red emission maximized at 710 nm in cyclohexane with an anomalously large Stokes shift of 12 230 cm-1. Upon methylation on the thiol group, 3MeNTF, lacking the thiol proton, exhibits a normal Stokes-shifted emission at 472 nm. These, in combination with the computational approaches, lead to the conclusion of thiol-type ESIPT unambiguously. Further time-resolved study renders an unresolvable (180 fs) ESIPT rate for 3NTF, followed by a tautomer emission lifetime of 120 ps. In sharp contrast to 3NTF, both 3TF and 3-mercapto-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one (3FTF) are non-emissive. Detailed computational approaches indicate that all studied thiols undergo thermally favorable ESIPT. However, once forming the proton-transferred tautomer, the lone-pair electrons on the sulfur atom brings non-negligible nπ? contribution to the S1′ state (prime indicates the proton-transferred tautomer), for which the relaxation is dominated by the non-radiative deactivation. For 3NTF, the extension of π-electron delocalization by the diethylamino electron-donating group endows the S1′ state primarily in the ππ? configuration, exhibiting the prominent tautomer emission. The results open a new chapter in the field of ESIPT, covering the non-canonical sulfur intramolecular H-bond and its associated ESIPT at ambient temperature.