870753-34-7

Basic information

• Product Name: N,N'-(9-borabicyclo[3.3.1]-non-9-yl)-5-mesityldipyrrin
• CAS NO: 870753-34-7
• Molecular Weight: 382.357
• Mol File: 870753-34-7.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: N,N'-(9-borabicyclo[3.3.1]-non-9-yl)-5-mesityldipyrrin(CAS DataBase Reference)
• NIST Chemistry Reference: N,N'-(9-borabicyclo[3.3.1]-non-9-yl)-5-mesityldipyrrin(870753-34-7)
• EPA Substance Registry System: N,N'-(9-borabicyclo[3.3.1]-non-9-yl)-5-mesityldipyrrin(870753-34-7)

Safety Data

• Hazardous Substances Data: 870753-34-7(Hazardous Substances Data)

Upstream product

• 118762-53-1 (Z)-2-(phenyl(2H-pyrrol-2-ylidene)methyl)-1H-pyrrole 
• 62731-43-5 9-BBN triflate 

Relevant articles and documents

Structural control of the photodynamics of boron-dipyrrin complexes

Boron-dipyrrin chromophpres containing a 5-aryl group with or without internal steric hindrance toward aryl rotation have been synthesized and then characterized via X-ray diffraction, static and time-resolved optical spectroscopy, and theory. Compounds with a 5-phenyl or 5-(4-terf-butylphenyl) group show low fluorescence yields (～0.06) and short excited-singlet-state lifetimes (～500 ps), and decay primarily (>90%) by nonradiative internal conversion to the ground state. In contrast, sterically hindered analogues having an o-tolyl or mesityl group at the 5-position exhibit high fluorescence yields (～0.9) and long excited-state lifetimes (～6 ns). The X-ray structures indicate that the phenyl or 4-terf-butylphenyl ring lies at an angle of ～60° with respect to the dipyrrin framework whereas the angle is ～80° for mesityl or o-tolyl groups. The calculated potential energy surface for the phenyl-substituted complex indicates that the excited state has a second, lower energy minimum in which the nonhindered aryl ring rotates closer to the mean plane of the dipyrrin, which itself undergoes some distortion. This relaxed, distorted excited-state conformation has low radiative probability as well as a reduced energy gap from the ground state supporting a favorable vibrational overlap factor for nonradiative deactivation. Such a distorted conformation is energetically inaccessible in a complex bearing the sterically hindered o-tolyl or mesityl group at the 5-position, leading to a high radiative probability involving conformations at or near the initial Franck-Condon form of the excited state. These combined results demonstrate the critical role of aryl-ring rotation in governing the excited-state dynamics of this class of widely used dyes.