TY  - JOUR
A1  - Sperlich, Eric
A1  - Köckerling, Martin
T1  - [Nb6Cl14(pyrazine)(4)], a versatile precursor for ligand-supported hexanuclear niobium cluster compounds: synthesis, characterization, follow-up reactions, and intermolecular interactions
JF  - Inorganic chemistry
N2  - The compound [Nb6Cl14(pyrazine)(4)]center dot 2CH(2)Cl(2) (1) was investigated for its suitability as a starting compound for new ligand-supported hexanuclear niobium cluster compounds. The synthesis, stability to air and increased temperature, solubility and usability for subsequent reactions of 1, and purification and separation of the reaction products are discussed. The compounds with cluster units [Nb6Cl14L4], where L = iso-quinoline N-oxides (2), 1,1-dimethylethylenediamines (3), or thiazoles (4), and [Nb6Cl14(PEt3)(3.76)(Et3PO)(0.24)]-[Nb6Cl14(MeCN)(4)]center dot 4MeCN (5) are presented as follow-up products. The crystal structures of compounds 1-5 are analyzed, and the structures are discussed with respect to their intraand intermolecular bonding situations and crystal packing. In addition to hydrogen bonds and pi-pi interactions, the appearance of chalcogen and halogen bonds and lone pair-pi interactions between Nb-6 cluster units was observed for the first time.
KW  - Cluster chemistry
KW  - crystals
KW  - ligands
KW  - molecules
KW  - transition metals
Y1  - 2022
U6  - https://doi.org/10.1021/acs.inorgchem.1c03109
SN  - 0020-1669
SN  - 1520-510X
VL  - 61
IS  - 5
SP  - 2409
EP  - 2420
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - GEN
A1  - Ehlert, Christopher
A1  - Holzweber, Markus
A1  - Lippitz, Andreas
A1  - Unger, Wolfgang E. S.
A1  - Saalfrank, Peter
T1  - A detailed assignment of NEXAFS resonances of imidazolium based ionic liquids
N2  - In Near Edge X-Ray Absorption Fine Structure (NEXAFS) spectroscopy X-Ray photons are used to excite tightly bound core electrons to low-lying unoccupied orbitals of the system. This technique offers insight into the electronic structure of the system as well as useful structural information. In this work, we apply NEXAFS to two kinds of imidazolium based ionic liquids ([CnC1im]+[NTf2]- and [C4C1im]+[I]-). A combination of measurements and quantum chemical calculations of C K and N K NEXAFS resonances is presented. The simulations, based on the transition potential density functional theory method (TP-DFT), reproduce all characteristic features observed by the experiment. Furthermore, a detailed assignment of resonance features to excitation centers (carbon or nitrogen atoms) leads to a consistent interpretation of the spectra.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 315 
KW  - ray absorption-spectroscopy
KW  - fine-structure
KW  - spectra
KW  - simulations
KW  - molecules
KW  - dynamics
KW  - graphene
KW  - surface
KW  - salts
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-394417
SP  - 8654
EP  - 8661
ER  - 
TY  - GEN
A1  - Banerjee, Shiladitya
A1  - Saalfrank, Peter
T1  - Vibrationally resolved absorption, emission and resonance Raman spectra of diamondoids
BT  - a study based on time-dependent correlation functions
N2  - The time-dependent approach to electronic spectroscopy, as popularized by Heller and coworkers in the 1980's, is applied here in conjunction with linear-response, time-dependent density functional theory to study vibronic absorption, emission and resonance Raman spectra of several diamondoids. Two-state models, the harmonic and the Condon approximations, are used for the calculations, making them easily applicable to larger molecules. The method is applied to nine pristine lower and higher diamondoids: adamantane, diamantane, triamantane, and three isomers each of tetramantane and pentamantane. We also consider a hybrid species “Dia = Dia” – a shorthand notation for a recently synthesized molecule comprising two diamantane units connected by a C[double bond, length as m-dash]C double bond. We resolve and interpret trends in optical and vibrational properties of these molecules as a function of their size, shape, and symmetry, as well as effects of “blending” with sp2-hybridized C-atoms. Time-dependent correlation functions facilitate the computations and shed light on the vibrational dynamics following electronic transitions.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 238 
KW  - adamantane
KW  - models
KW  - molecules
KW  - states
KW  - thermochemistry
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-94542
SP  - 144
EP  - 158
ER  -