TY - DATA T1 - Anion Template Effect on the Self-Assembly and Interconversion of Metallacyclophanes PY - 2005/09/21 AU - Cristian Saul Campos-Fernández AU - Brandi L. Schottel AU - Helen T. Chifotides AU - Jitendra K. Bera AU - John Bacsa AU - John M. Koomen AU - David H. Russell AU - Kim R. Dunbar UR - https://acs.figshare.com/articles/dataset/Anion_Template_Effect_on_the_Self_Assembly_and_Interconversion_of_Metallacyclophanes/3266956 DO - 10.1021/ja052108q.s007 L4 - https://ndownloader.figshare.com/files/5104678 KW - Anion Template Effect KW - BF 4 KW - anion KW - bptz KW - SbF 6 KW - Ni KW - presence KW - CH 3 CN KW - Zn KW - IO KW - ClO 4 N2 - Reactions of 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine (bptz) with solvated first-row transition metals M(II) (M(II) = Ni, Zn, Mn, Fe, Cu) have been explored with emphasis on the factors that influence the identity of the resulting cyclic products for Ni(II) and Zn(II). The relatively small anions, namely [ClO4]- and [BF4]-, lead to the formation of molecular squares [{M4(bptz)4(CH3CN)8}⊂X][X]7, (M = Zn(II), Ni(II); X = [BF4]-, [ClO4]-), whereas the larger anion [SbF6]- favors the molecular pentagon [{Ni5(bptz)5-(CH3CN)10}⊂SbF6][SbF6]9. The molecular pentagon easily converts to the square in the presence of excess [BF4]-, [ClO4]-, and [I]- anions, whereas the Ni(II) square can be partially converted to the less stable pentagon under more forcing conditions in the presence of excess [SbF6]- ions. No evidence for the molecular square being in equilibrium with the pentagon was observed in the ESI-MS spectra of the individual square and pentagon samples. Anion-exchange reactions of the encapsulated ion in [{Ni4(bptz)4(CH3CN)8}⊂ClO4][ClO4]7 reveal that a larger anion such as [IO4]- cannot replace [ClO4]- inside the cavity, but that the linear [Br3]- anion is capable of doing so. ESI-MS studies of the reaction between [Ni(CH3CN)6][NO3]2 and bptz indicate that the product is trinuclear. Mass spectral studies of the bptz reactions with Mn(II), Fe(II), and Cu(II), in the presence of [ClO4]- anions, support the presence of molecular squares. The formation of the various metallacyclophanes is discussed in light of the factors that influence these self-assembly reactions, such as choice of metal ion, anion, and solvent. ER -