TY  - JOUR
A1  - Schwarze, Thomas
A1  - Sperlich, Eric
A1  - Müller, Thomas
A1  - Kelling, Alexandra
A1  - Holdt, Hans-Jürgen
T1  - Synthesis efforts of acyclic bis(monoalkylamino)maleonitriles and macrocyclic bis(dialkylamino)maleonitriles as fluorescent probes for cations and a new colorimetric copper(II) chemodosimeter
JF  - Helvetica chimica acta
N2  - In this article, we report on the synthesis of acyclic bis(monoalkylamino)maleonitriles and on the intended synthesis of macrocyclic bis(dialkylamino)maleonitriles to get fluorescent probes for cations. During our efforts to synthesize macrocyclic bis(dialkylamino)maleonitriles, we were only able to isolate macrocyclic bis(dialkylamino)-fumaronitriles. The synthesis of macrocyclic bis(dialkylamino)maleonitriles is challenging, due to the fact that bis-(dialkylamino)fumaronitriles are thermodynamically more stable than the corresponding bis(dialkylamino)-maleonitriles. Further, it turned out that the acyclic bis(monoalkylamino)maleonitriles and macrocyclic bis-(dialkylamino)fumaronitriles are no suitable tools to detect cations by a strong fluorescence enhancement. Further, only the bis(monoalkylamino)maleonitriles, which are bearing a 2-pyridyl unit as an additional complexing unit, are able to selectively recognize copper(II) by a color change from yellow to red.
KW  - copper
KW  - fumaronitrile
KW  - ligands
KW  - macrocycles
KW  - maleonitrile
Y1  - 2021
U6  - https://doi.org/10.1002/hlca.202100028
SN  - 1522-2675
VL  - 104
IS  - 6
SP  - e2100028
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
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  -