Pretražite po imenu i prezimenu autora, mentora, urednika, prevoditelja

Napredna pretraga

Pregled bibliografske jedinice broj: 262034

Automerization of Cyclobutadiene and its Barrier Height-An Ab Initio Study


Eckert-Maksić, Mirjana; Vazdar, Mario; Barbatti, Mario; Lischka, Hans; Maksić, Zvonimir B.
Automerization of Cyclobutadiene and its Barrier Height-An Ab Initio Study // 3rd Meeting of the COST working group D26/0014/03 Intrinsic Reactivity of new Molecular Materials / Eckert-Maksić, Mirjana (ur.).
Zagreb: Institut Ruđer Bošković, 2006. (poster, nije recenziran, sažetak, znanstveni)


CROSBI ID: 262034 Za ispravke kontaktirajte CROSBI podršku putem web obrasca

Naslov
Automerization of Cyclobutadiene and its Barrier Height-An Ab Initio Study

Autori
Eckert-Maksić, Mirjana ; Vazdar, Mario ; Barbatti, Mario ; Lischka, Hans ; Maksić, Zvonimir B.

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
3rd Meeting of the COST working group D26/0014/03 Intrinsic Reactivity of new Molecular Materials / Eckert-Maksić, Mirjana - Zagreb : Institut Ruđer Bošković, 2006

Skup
3rd Meeting of the COST working group D26/0014/03 Intrinsic Reactivity of new Molecular Materials (3 ; 2006)

Mjesto i datum
Zagreb, Hrvatska, 28.-29.04.2006

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
cyclobutadiene; bond flipping automerization; MR-AQCC computations

Sažetak
Cyclobutadiene has been fascinating experimental and theoretical chemists for many decades1. Inspite of many efforts, some of its features are still not quite understood. The barrier height of the bond flipping automerization process is among them. The experimental measurements yield for the height a large margin between 1.6 and 10.0 kcal/mol2, 3. In particular, the 13C NMR experiment indicates that the activation energy for automerization is no more than 2.5 kcal/mol for tri-t-butylcyclobutadiene3. This value is at odds with the most accurate MR-CCSD(T) calculations performed so far by Balkova and Bartlett4, giving the barrier of 6.6 kcal/mol. In order to resolve this disagreement, we have undertaken a series of multireference average quadratic coupled cluster calculations. The most sophisticated treatment involved the state averaging over four states (11Ag, 21Ag, 11B3g, and 13B3g) and the MR-AQCC computations based on the correlation consistent augmented aug'-cc-pVTZ functions, where aug' implies that the f-functions on carbon atoms and d-functions on hydrogen atoms were deleted. It appears that the barrier height, given by the total molecular energies, is 8.3 kcal/mol. The difference with the first triplet state at the squared transition state geometry is rather low, being 5.4 kcal/mol. The influence of the vibrational energy on the barrier will be discussed.

Izvorni jezik
Engleski

Znanstvena područja
Kemija



POVEZANOST RADA


Projekti:
0098056

Ustanove:
Institut "Ruđer Bošković", Zagreb

Profili:

Avatar Url Mirjana Maksić (autor)

Avatar Url Mario Vazdar (autor)

Avatar Url Zvonimir Maksić (autor)


Citiraj ovu publikaciju:

Eckert-Maksić, Mirjana; Vazdar, Mario; Barbatti, Mario; Lischka, Hans; Maksić, Zvonimir B.
Automerization of Cyclobutadiene and its Barrier Height-An Ab Initio Study // 3rd Meeting of the COST working group D26/0014/03 Intrinsic Reactivity of new Molecular Materials / Eckert-Maksić, Mirjana (ur.).
Zagreb: Institut Ruđer Bošković, 2006. (poster, nije recenziran, sažetak, znanstveni)
Eckert-Maksić, M., Vazdar, M., Barbatti, M., Lischka, H. & Maksić, Z. (2006) Automerization of Cyclobutadiene and its Barrier Height-An Ab Initio Study. U: Eckert-Maksić, M. (ur.)3rd Meeting of the COST working group D26/0014/03 Intrinsic Reactivity of new Molecular Materials.
@article{article, editor = {Eckert-Maksi\'{c}, M.}, year = {2006}, keywords = {cyclobutadiene, bond flipping automerization, MR-AQCC computations}, title = {Automerization of Cyclobutadiene and its Barrier Height-An Ab Initio Study}, keyword = {cyclobutadiene, bond flipping automerization, MR-AQCC computations}, publisher = {Institut Ru\djer Bo\v{s}kovi\'{c}}, publisherplace = {Zagreb, Hrvatska} }
@article{article, editor = {Eckert-Maksi\'{c}, M.}, year = {2006}, keywords = {cyclobutadiene, bond flipping automerization, MR-AQCC computations}, title = {Automerization of Cyclobutadiene and its Barrier Height-An Ab Initio Study}, keyword = {cyclobutadiene, bond flipping automerization, MR-AQCC computations}, publisher = {Institut Ru\djer Bo\v{s}kovi\'{c}}, publisherplace = {Zagreb, Hrvatska} }




Contrast
Increase Font
Decrease Font
Dyslexic Font