Self-assembly of a family of suprametallomacrocycles: revisiting an o-carborane bisterpyridyl building block.
The self-assembly of the o-carborane-based, bisterpyridyl monomer, 1,2-bis[4'-(4-ethynylphenyl)-2,2':6',2''-terpyridine]-o-carborane, utilizing either Zn(II) or Fe(II) in a precise metal : ligand ratio (1 : 1), generated a family of metallomacrocycles that were studied via ESI-TWIM-MS, (1)H NMR, and 2D NMR (COSY, NOESY). Under kinetic control, via formation of Fe(II) complexes, the main cyclic product was triangular, as is typical of 60°-based bisligands. Under thermodynamic control using more labile transition metal complexes, e.g. Zn(II), the ratio of cyclic species was found to be concentration and temperature dependent, and under an adequate entropic driving force, the cyclic dimer was formed. This system was probed via variable temperature NMR to reveal dynamic equilibrium between the entropically favored dimer and enthalpically favored trimer.
Department of Polymer Science, The University of Akron, Akron, OH 44325-4717, USA. newkome@uakron.edu wesdemiotis@uakron.edu.
James M
JM
Ludlow Iii
Masato
M
Tominaga
Yoshiki
Y
Chujo
Anthony
A
Schultz
Xiaocun
X
Lu
Tingzheng
T
Xie
Kai
K
Guo
Charles N
CN
Moorefield
Chrys
C
Wesdemiotis
George R
GR
Newkome
D001896:Boron Compounds / Q000737:chemistry*; D056831:Coordination Complexes / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D047028:Macrocyclic Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D011725:Pyridines / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry
C517923:(2,2'-6',2'')-terpyridine; D001896:Boron Compounds; D056831:Coordination Complexes; D047028:Macrocyclic Compounds; D011725:Pyridines; D007501:Iron; D015032:Zinc