Structure and Electronic Properties of an Expanded Terpyridine Complex of Nickel(II) [Ni(ddpd)2](BF4)2

A Heteroleptic Push-Pull Substituted Iron(II) Bis(tridentate) Complex with Low-Energy Charge-Transfer States

A heteroleptic iron(II) complex [Fe(dcpp)(ddpd)](2+) with a strongly electron-withdrawing ligand (dcpp, 2,6-bis(2-carboxypyridyl)pyridine) and a strongly electron-donating tridentate tripyridine ligand (ddpd, N,N'-dimethyl-N,N'-dipyridine-2-yl-pyridine-2,6-diamine) is reported. Both ligands form six-membered chelate rings with the iron center, inducing a strong ligand field. This results in a high-energy, high-spin state ((5) T2 , (t2g )(4) (eg *)(2) ) and a low-spin ground state ((1) A1 , (t2g )(6) (eg *)(0) ). The intermediate triplet spin state ((3) T1 , (t2g )(5) (eg *)(1) ) is suggested to be between these states on the basis of the rapid dynamics after photoexcitation. The low-energy …

Effect of chelate ring expansion on Jahn-Teller distortion and Jahn-Teller dynamics in copper(II) complexes.

The expanded ligand N,N'-dimethyl-N,N'-dipyridin-2-yl-pyridin-2,6-diamine (ddpd) coordinates to copper(II) ions in a meridional fashion giving the dicationic complex mer-[Cu(ddpd)(2)](BF(4))(2) (1). In the solid state at temperatures below 100 K the cations of 1 localize in Jahn-Teller elongated CuN(6) polyhedra with the longest Cu-N bond pointing in the molecular x or y directions while the z axis is constrained by the tridentate ddpd ligand. The elongated polyhedra are ordered in an antiferrodistortive way giving an idealized zincblende structure. At higher temperature dynamically averaged (fluxional) polyhedra in the molecular x/y directions are observed by multifrequency variable temper…

Coordination of expanded terpyridine ligands to cobalt

Abstract The tridentate expanded terpyridine-like ligand N,N′-dimethyl-N,N′-dipyridin-2-yl-pyridin-2,6-diamine (ddpd) and [Co(H2O)6](BF4)2 give the high-spin complex mer-[Co(ddpd)2](BF4)2 with a tetragonally compressed CoN6 coordination geometry according to X-ray diffraction and SQUID measurements. UV–Vis–NIR spectra indicate a large ligand field splitting close to the high-spin/low-spin crossover point. Oxidation of the CoII complex to CoIII is achieved with silver triflate. The self exchange between high-spin CoII and low-spin CoIII is slow on the NMR time scale.

CCDC 1016554: Experimental Crystal Structure Determination

Related Article: Andreas K. C. Mengel, Christoph Förster, Aaron Breivogel, Katharina Mack, Julian R. Ochsmann, Frédéric Laquai, Vadim Ksenofontov, Katja Heinze|2015|Chem.-Eur.J.|21|704|doi:10.1002/chem.201404955

CCDC 1829268: Experimental Crystal Structure Determination

Related Article: Matthias Dorn, Katharina Mack, Luca M. Carrella, Eva Rentschler, Christoph Förster, Katja Heinze|2018|Z.Anorg.Allg.Chem.|644|706|doi:10.1002/zaac.201800101

CCDC 1016552: Experimental Crystal Structure Determination

Related Article: Andreas K. C. Mengel, Christoph Förster, Aaron Breivogel, Katharina Mack, Julian R. Ochsmann, Frédéric Laquai, Vadim Ksenofontov, Katja Heinze|2015|Chem.-Eur.J.|21|704|doi:10.1002/chem.201404955

CCDC 1016553: Experimental Crystal Structure Determination

Related Article: Andreas K. C. Mengel, Christoph Förster, Aaron Breivogel, Katharina Mack, Julian R. Ochsmann, Frédéric Laquai, Vadim Ksenofontov, Katja Heinze|2015|Chem.-Eur.J.|21|704|doi:10.1002/chem.201404955

CCDC 1016551: Experimental Crystal Structure Determination

Related Article: Andreas K. C. Mengel, Christoph Förster, Aaron Breivogel, Katharina Mack, Julian R. Ochsmann, Frédéric Laquai, Vadim Ksenofontov, Katja Heinze|2015|Chem.-Eur.J.|21|704|doi:10.1002/chem.201404955