Pseudo-bimolecular [2+2] cycloaddition studied by time-resolved photoelectron spectroscopy.
نویسندگان
چکیده
The first study of pseudo-bimolecular cycloaddition reaction dynamics in the gas phase is presented. We used femtosecond time-resolved photoelectron spectroscopy (TRPES) to study the [2+2] photocycloaddition in the model system pseudo-gem-divinyl[2.2]paracyclophane. From X-ray crystal diffraction measurements we found that the ground-state molecule can exist in two conformers; a reactive one in which the vinyl groups are immediately situated for [2+2] cycloaddition and a nonreactive conformer in which they point in opposite directions. From the measured S(1) lifetimes we assigned a clear relation between the conformation and the excited-state reactivity; the reactive conformer has a lifetime of 13 ps, populating the ground state through a conical intersection leading to [2+2] cycloaddition, whereas the nonreactive conformer has a lifetime of 400 ps. Ab initio calculations were performed to locate the relevant conical intersection (CI) and calculate an excited-state [2+2] cycloaddition reaction path. The interpretation of the results is supported by experimental results on the similar but nonreactive pseudo-para-divinyl[2.2]paracyclophane, which has a lifetime of more than 500 ps in the S(1) state.
منابع مشابه
The nonradiative decay of the allyl radical excited B 2 A 1 state studied by picosecond time-resolved photoelectron spectroscopy
متن کامل
Rotationally resolved photoionization dynamics of hot CO fragmented from OCS
Articles you may be interested in Study of ultrafast dynamics of 2-picoline by time-resolved photoelectron imaging Coherent polyatomic dynamics studied by femtosecond time-resolved photoelectron spectroscopy: Dissociation of vibrationally excited C S 2 in the 6 s and 4 d Rydberg states Rovibrational photoionization dynamics of methyl and its isotopomers studied by high-resolution photoionizatio...
متن کاملCycloaddition reaction of furan with Si(100)-2×1
Articles you may be interested in Adsorption mechanisms of isoxazole and oxazole on Si(100)-2 × 1 surface: Si–N dative bond addition vs. [4+2] cycloaddition J. The adsorption configuration of furan on Si͑100͒-2ϫ1 at 125 K has been investigated using x-ray photoelectron spectroscopy ͑XPS͒, ultraviolet photoelectron spectroscopy ͑UPS͒, high resolution electron energy loss spectroscopy ͑HREELS͒, and semie...
متن کاملFemtosecond energy- and angle-resolved photoelectron spectroscopy
Articles you may be interested in Comment on " Photoelectron angular distributions as a probe of alignment in a polyatomic molecule: Picosecond time-and angle-resolved photoelectron spectroscopy of S1 p-difluorobenzene " [J. Coherent polyatomic dynamics studied by femtosecond time-resolved photoelectron spectroscopy: Dissociation of vibrationally excited C S 2 in the 6 s and 4 d Rydberg states ...
متن کاملTime-resolved photoelectron spectroscopy of wavepackets through a conical intersection in NO2.
We report the results of theoretical studies of the time-resolved femtosecond photoelectron spectroscopy of quantum wavepackets through the conical intersection between the first two (2)A' states of NO(2). The Hamiltonian explicitly includes the pump-pulse interaction, the nonadiabatic coupling due to the conical intersection between the neutral states, and the probe interaction between the neu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chemistry
دوره 17 14 شماره
صفحات -
تاریخ انتشار 2011