Author: Andreas K. C. Mengel

0000000000342064

AUTHOR

Andreas K. C. Mengel

showing 10 related works from this author

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

2014

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 …

Ligand field theorySpin statesLigandOrganic ChemistryGeneral ChemistryPhotochemistryElectrochemistryCatalysislaw.inventionCrystallographychemistry.chemical_compoundchemistrylawExcited statePyridineGround stateElectron paramagnetic resonanceChemistry - A European Journal

researchProduct

A Bis(tridentate)cobalt Polypyridine Complex as Mediator in Dye‐Sensitized Solar Cells

2015

Dye-sensitized solar cells equipped with cationic and neutral RuII-based sensitizers [Ru(ddpd){tpy(COOH)3}]2+ [12+; ddpd = N,N′-dimethyl-N,N′-di(pyridin-2-yl)pyridin-2,6-diamine, tpy(COOH)3 = 2,2″6′,2″-terpyridine-4,4′,4″-tricarboxylic acid] and [Ru(ddpd){tpy(COOH)(COO)2}] (2) with and without the coadsorbent chenodeoxycholic acid were constructed with I3–/I– or the CoIII/II-based redox mediators [Co(bpy)3]3+/2+ (33+/2+; bpy = 2,2′-bipyridine) and [Co(ddpd)2]3+/2+ (43+/2+) in the presence of LiClO4 and 4-tert-butylpyridine. The best photovoltaic performance was achieved by using the 43+/2+ shuttle and the neutral sensitizer 2 without coadsorbent. The higher short-circuit photocurrent densit…

Inorganic ChemistryElectron transferDye-sensitized solar cellCrystallographyPolypyridine complexChemistryKineticsCationic polymerizationchemistry.chemical_elementPhotochemistryRedoxCobaltRutheniumEuropean Journal of Inorganic Chemistry

researchProduct

Boosting Vis/NIR Charge-Transfer Absorptions of Iron(II) Complexes by N-Alkylation and N-Deprotonation in the Ligand Backbone.

2017

Reversing the 3MLCT / 3MC excited state order in iron(II) complexes is a challenging objective, yet would finally result in longsought luminescent transition metal complexes with an earthabundant central ion. One approach to achieve this goal is based on low-energy charge transfer absorptions in combination with a strong ligand field. Coordinating electron rich and electron poor tridentate oligopyridine ligands with large bite angles at iron(II) enables both low-energy MLCT absorption bands around 590 nm and a strong ligand field. Variations of the electron rich ligand by introducing longer alkyl substituents destabilizes the iron(II) complex towards ligand substitution reactions while hard…

chemistry.chemical_classificationLigand field theory010405 organic chemistryChemistryLigandBand gapOrganic ChemistryGeneral Chemistry010402 general chemistryPhotochemistry01 natural sciencesCatalysis0104 chemical sciencesDeprotonationTransition metalExcited stateDensity functional theoryAlkylChemistry (Weinheim an der Bergstrasse, Germany)

researchProduct

Strongly Coupled Cyclometalated Ruthenium Triarylamine Chromophores as Sensitizers for DSSCs

2016

A series of anchor-functionalized cyclometalated bis(tridentate) ruthenium(II) triarylamine hybrids [Ru(dbp-X)(tctpy)](2-) [2 a](2-) -[2 c](2-) (H3 tctpy=2,2';6',2''-terpyridine-4,4',4''-tricarboxylic acid; dpbH=1,3-dipyridylbenzene; X=N(4-C6 H4 OMe)2 ([2 a](2-) ), NPh2 ([2 b](2-) ), N-carbazolyl [2 c](2-) ) was synthesized and characterized. All complexes show broad absorption bands in the range 300-700 nm with a maximum at about 545 nm. Methyl esters [Ru(Me3 tctpy)(dpb-X)](+) [1 a](+) -[1 c](+) are oxidized to the strongly coupled mixed-valent species [1 a](2+) -[1 c](2+) and the Ru(III) (aminium) complexes [1 a](3+) -[1 c](3+) at comparably low oxidation potentials. Theoretical calculati…

chemistry.chemical_classification010405 organic chemistryChemistryOrganic ChemistryCenter (category theory)chemistry.chemical_elementGeneral ChemistryTricarboxylic acidChromophore010402 general chemistryPhotochemistry01 natural sciencesMedicinal chemistryCatalysis0104 chemical sciencesRutheniumMetalBipyridinechemistry.chemical_compoundDye-sensitized solar cellvisual_artvisual_art.visual_art_mediumCobaltChemistry - A European Journal

researchProduct

CCDC 1016554: Experimental Crystal Structure Determination

2014

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

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parametersbis((pyridine-26-diyl)bis((pyridin-2-yl)methanone))-iron bis(hexafluorophosphate) acetonitrile solvateExperimental 3D Coordinates

researchProduct

CCDC 1526745: Experimental Crystal Structure Determination

2017

Related Article: Andreas K. C. Mengel, Christian Bissinger, Matthias Dorn, Oliver Back, Christoph Förster, Katja Heinze|2017|Chem.-Eur.J.|23|7920|doi:10.1002/chem.201700959

bis(NN'-dihexyl-NN'-bis(pyridin-2-yl)pyridine-26-diamine)-iron bis(hexafluorophosphate)Space GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates

researchProduct

CCDC 1016552: Experimental Crystal Structure Determination

2014

Space GroupCrystallographyCrystal SystemCrystal Structurebis(NN'-dimethyl-NN'-di(pyridin-2-yl)pyridine-26-diamine)-iron bis(hexafluorophosphate) acetonitrile solvateCell ParametersExperimental 3D Coordinates

researchProduct

CCDC 1526744: Experimental Crystal Structure Determination

2017

Related Article: Andreas K. C. Mengel, Christian Bissinger, Matthias Dorn, Oliver Back, Christoph Förster, Katja Heinze|2017|Chem.-Eur.J.|23|7920|doi:10.1002/chem.201700959

Space GroupCrystallography(NN'-bis(pyridin-2-yl)pyridine-26-diamine)-(pyridine-26-diylbis(pyridin-2-ylmethanone))-iron bis(hexafluorophosphate) hydrateCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates

researchProduct

CCDC 1016553: Experimental Crystal Structure Determination

2014

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters(NN'-dimethyl-NN'-di(pyridin-2-yl)pyridine-26-diamine)-((pyridine-26-diyl)bis((pyridin-2-yl)methanone))-iron bis(hexafluorophosphate) acetonitrile solvateExperimental 3D Coordinates

researchProduct

CCDC 1016551: Experimental Crystal Structure Determination

2014

bis(NN'-dimethyl-NN'-di(pyridin-2-yl)pyridine-26-diamine)-iron bis(tetrafluoroborate) acetonitrile solvateSpace GroupCrystallographyCrystal SystemCrystal StructureCell ParametersExperimental 3D Coordinates

researchProduct