TY - JOUR
T1 - A Series of [Co(Mabiq)Cl2-n] (n = 0, 1, 2) Compounds and Evidence for the Elusive Bimetallic Form
AU - Puttock, Emma V.
AU - Banerjee, Priyabrata
AU - Kaspar, Manuel
AU - Drennen, Liam
AU - Yufit, Dmitry S.
AU - Bill, Eckhard
AU - Sproules, Stephen
AU - Hess, Corinna R.
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/6/15
Y1 - 2015/6/15
N2 - The synthesis and characterization of a series of cobalt compounds, coordinated by the redox-active macrocyclic biquinazoline ligand, Mabiq [2-4:6-8-bis(3,3,4,4-tetramethyldihydropyrrolo)-10-15-(2,2′-biquinazolino)-[15]-1,3,5,8,10,14-hexaene-1,3,7,9,11,14-N6], is presented. The series includes the monometallic Co(Mabiq)Cl2 (1), Co(Mabiq)Cl (2), and Co(Mabiq) (4), with formal metal oxidation states of 3+ → 1+. A binuclear cobaltous compound, Co2(Mabiq)Cl3 (3), also was obtained, providing the first evidence for the ability of the Mabiq ligand to coordinate two metal ions. The electronic structures of the paramagnetic 2 and 3 were examined by electron paramagnetic resonance spectroscopy and magnetic susceptibility studies. The CoII ion that resides in the N4-macrocylic cavity of 2 and 3 adopts a low-spin S = 1/2 configuration. The bypirimidine functionality in 3 additionally coordinates a high-spin S = 3/2 cobaltous ion in a tetrahedral environment. The two metal ions in 3 are weakly coupled by magnetometry. The square-planar, low-valent 4 offers one of a limited number of examples of structurally characterized N4-macrocyclic CoI compounds. Spectroscopic and density functional theory computational data suggest that a CoII(Mabiq•) description may be a reasonable alternative to the CoI formalism for this compound.
AB - The synthesis and characterization of a series of cobalt compounds, coordinated by the redox-active macrocyclic biquinazoline ligand, Mabiq [2-4:6-8-bis(3,3,4,4-tetramethyldihydropyrrolo)-10-15-(2,2′-biquinazolino)-[15]-1,3,5,8,10,14-hexaene-1,3,7,9,11,14-N6], is presented. The series includes the monometallic Co(Mabiq)Cl2 (1), Co(Mabiq)Cl (2), and Co(Mabiq) (4), with formal metal oxidation states of 3+ → 1+. A binuclear cobaltous compound, Co2(Mabiq)Cl3 (3), also was obtained, providing the first evidence for the ability of the Mabiq ligand to coordinate two metal ions. The electronic structures of the paramagnetic 2 and 3 were examined by electron paramagnetic resonance spectroscopy and magnetic susceptibility studies. The CoII ion that resides in the N4-macrocylic cavity of 2 and 3 adopts a low-spin S = 1/2 configuration. The bypirimidine functionality in 3 additionally coordinates a high-spin S = 3/2 cobaltous ion in a tetrahedral environment. The two metal ions in 3 are weakly coupled by magnetometry. The square-planar, low-valent 4 offers one of a limited number of examples of structurally characterized N4-macrocyclic CoI compounds. Spectroscopic and density functional theory computational data suggest that a CoII(Mabiq•) description may be a reasonable alternative to the CoI formalism for this compound.
UR - http://www.scopus.com/inward/record.url?scp=84935837326&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.5b00636
DO - 10.1021/acs.inorgchem.5b00636
M3 - Article
AN - SCOPUS:84935837326
SN - 0020-1669
VL - 54
SP - 5864
EP - 5873
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 12
ER -