TY - JOUR
T1 - Novel metal-linked face-to-face porphyrazine dimer
AU - Zhong, Chang
AU - Zhao, Min
AU - Stern, Charlotte
AU - Barrett, Anthony G.M.
AU - Hoffman, Brian M.
PY - 2005/11/14
Y1 - 2005/11/14
N2 - We report the synthesis and physical studies of a novel porphyrazine (pz) dimer {1[Ni,Cu]}2, which has Ni(II) ions incorporated into the pz cores and is linked by two Cu(II) ions coordinated to bis(picolinamide) chelates attached to the pz periphery. {1[Ni,Cu]}2 was prepared from precursor pz 2 with a selenodiazole ring fused to the pz core. This ring was deprotected to form the diamino-pz 3, which reacted with 2 mol of picolinoyl chloride hydrochloride to form pz 1[2H,2H], with peripheral bis(picolinamide) chelates; this was metalated to form {1[Ni,Cu]}2. The crystal structures of 1[2H,2H] and {1[Ni,Cu]}2 are presented. The latter is a dimer in which parallel, face-to-face pz's with an average separation of 3.30 Å are linked through the peripheral picolinamide ligands by a pair of peripheral Cu(II) ions. Each Cu(II) is coordinated with distorted square-planar geometry by a picolinamide from each pz. In this report, we focus on the interaction of these two peripheral Cu(II) ions. We discuss the preparation and magnetic properties of the pz dimer complex {1[Ni,Cu]}2 with two Cu(II) ions in the peripheral chelate but a diamagnetic metal ion Ni(II) in the pz core. Although {1[Ni,Cu]}2 contains two Cu(II) ions (S = 1/2), we could detect no electron paramagnetic resonance signal, which suggests very strong antiferromagnetic exchange between those two Cu(II) ions. Temperature-dependent magnetic susceptibility measurement gives an exchange splitting between the S = 0 ground state and the excited triplet state of Δ = 660 cm-1.
AB - We report the synthesis and physical studies of a novel porphyrazine (pz) dimer {1[Ni,Cu]}2, which has Ni(II) ions incorporated into the pz cores and is linked by two Cu(II) ions coordinated to bis(picolinamide) chelates attached to the pz periphery. {1[Ni,Cu]}2 was prepared from precursor pz 2 with a selenodiazole ring fused to the pz core. This ring was deprotected to form the diamino-pz 3, which reacted with 2 mol of picolinoyl chloride hydrochloride to form pz 1[2H,2H], with peripheral bis(picolinamide) chelates; this was metalated to form {1[Ni,Cu]}2. The crystal structures of 1[2H,2H] and {1[Ni,Cu]}2 are presented. The latter is a dimer in which parallel, face-to-face pz's with an average separation of 3.30 Å are linked through the peripheral picolinamide ligands by a pair of peripheral Cu(II) ions. Each Cu(II) is coordinated with distorted square-planar geometry by a picolinamide from each pz. In this report, we focus on the interaction of these two peripheral Cu(II) ions. We discuss the preparation and magnetic properties of the pz dimer complex {1[Ni,Cu]}2 with two Cu(II) ions in the peripheral chelate but a diamagnetic metal ion Ni(II) in the pz core. Although {1[Ni,Cu]}2 contains two Cu(II) ions (S = 1/2), we could detect no electron paramagnetic resonance signal, which suggests very strong antiferromagnetic exchange between those two Cu(II) ions. Temperature-dependent magnetic susceptibility measurement gives an exchange splitting between the S = 0 ground state and the excited triplet state of Δ = 660 cm-1.
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U2 - 10.1021/ic050788s
DO - 10.1021/ic050788s
M3 - Article
C2 - 16270965
AN - SCOPUS:28244469726
VL - 44
SP - 8272
EP - 8276
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 23
ER -