000126452 001__ 126452
000126452 005__ 20240731103358.0
000126452 0247_ $$2doi$$a10.1021/acscatal.3c00764
000126452 0248_ $$2sideral$$a133919
000126452 037__ $$aART-2023-133919
000126452 041__ $$aeng
000126452 100__ $$0(orcid)0000-0003-1115-6759$$aGeer, A. M.$$uUniversidad de Zaragoza
000126452 245__ $$aHomotropic cooperativity in iron-catalyzed alkyne cyclotrimerizations
000126452 260__ $$c2023
000126452 5060_ $$aAccess copy available to the general public$$fUnrestricted
000126452 5203_ $$aEnhancing catalytic activity through synergic effects is a current challenge in homogeneous catalysis. In addition to the well-established metal–metal and metal–ligand cooperation, we showcase here an example of self-activation by the substrate in controlling the catalytic activity of the two-coordinate iron complex [Fe(2,6-Xyl2C6H3)2] (1, Xyl = 2,6-Me2C6H3). This behavior was observed for aryl acetylenes in their regioselective cyclotrimerization to 1,2,4-(aryl)-benzenes. Two kinetically distinct regimes are observed dependent upon the substrate-to-catalyst ratio ([RC≡CH]0/[1]0), referred to as the low ([RC≡CH]0/[1]0 < 40) and high ([RC≡CH]0/[1]0 > 40) regimes. Both showed sigmoidal kinetic response, with positive Hill indices of 1.85 and 3.62, respectively, and nonlinear Lineweaver–Burk replots with an upward curvature, which supports positive substrate cooperativity. Moreover, two alkyne molecules participate in the low regime, whereas up to four are involved in the high regime. The second-order rate dependence on 1 indicates that binuclear complexes are the catalytically competent species in both regimes, with that in the high one being 6 times faster than that involved in the low one. Moreover, Eyring plot analyses revealed two different catalytic cycles, with a rate-determining step more endergonic in the low regime than in the high one, but with a more ordered transition state in the high regime than in the low one.
000126452 536__ $$9info:eu-repo/grantAgreement/ES/AEI/PID2020-119512GB-I00
000126452 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttp://creativecommons.org/licenses/by/3.0/es/
000126452 590__ $$a11.3$$b2023
000126452 592__ $$a3.847$$b2023
000126452 591__ $$aCHEMISTRY, PHYSICAL$$b23 / 178 = 0.129$$c2023$$dQ1$$eT1
000126452 593__ $$aChemistry (miscellaneous)$$c2023$$dQ1
000126452 593__ $$aCatalysis$$c2023$$dQ1
000126452 594__ $$a20.8$$b2023
000126452 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000126452 700__ $$0(orcid)0000-0002-2549-4487$$aNavarro, J.
000126452 700__ $$aAlamán-Valtierra, P.
000126452 700__ $$aColes, N. T.
000126452 700__ $$aKays, D. L.
000126452 700__ $$0(orcid)0000-0003-3306-0635$$aTejel, C.
000126452 7102_ $$12010$$2760$$aUniversidad de Zaragoza$$bDpto. Química Inorgánica$$cÁrea Química Inorgánica
000126452 773__ $$g13, 10 (2023), 6610-6618$$pACS catal.$$tACS CATALYSIS$$x2155-5435
000126452 8564_ $$s3546816$$uhttps://zaguan.unizar.es/record/126452/files/texto_completo.pdf$$yVersión publicada
000126452 8564_ $$s3267516$$uhttps://zaguan.unizar.es/record/126452/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000126452 909CO $$ooai:zaguan.unizar.es:126452$$particulos$$pdriver
000126452 951__ $$a2024-07-31-09:57:34
000126452 980__ $$aARTICLE