@article{WessigMatthesSchildeetal.2013, author = {Wessig, Pablo and Matthes, Annika and Schilde, Uwe and Kelling, Alexandra}, title = {Asymmetric synthesis of (1,5)Naphthalenophanes by Dehydro-Diels-Alder reaction}, series = {European journal of organic chemistry}, journal = {European journal of organic chemistry}, number = {11}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201201594}, pages = {2123 -- 2129}, year = {2013}, abstract = {An asymmetric variant of the dehydro-Diels-Alder (DDA) reaction has been developed and applied in the atropselective synthesis of various (1,5)naphthalenophanes. Whereas the suitability of the photochemically induced DDA (PDDA) was limited, the thermally induced DDA provided the desired product, depending on the chiral auxiliary used and the length of the linker, with nearly perfect stereoselectivity. Furthermore, the mechanism of the DDA was investigated by means of DFT calculations, and a stepwise mechanism involving 1,4-biradicals was suggested.}, language = {en} } @article{LinkerFudickarKellingetal.2013, author = {Linker, Torsten and Fudickar, Werner and Kelling, Alexandra and Schilde, Uwe}, title = {Crystal structure of dimethyl 1,4-dioxaspiro[4,5]dec-6-ene-(8R)-[(3,5-dinitrobenzoyl)oxa]-(2R,3R)-dica rboxylate, C19H18N2O12}, series = {Zeitschrift f{\"u}r Kristallographie : international journal for structural, physical and chemical aspects of crystalline materials ; New crystal structures}, volume = {228}, journal = {Zeitschrift f{\"u}r Kristallographie : international journal for structural, physical and chemical aspects of crystalline materials ; New crystal structures}, number = {2}, publisher = {De Gruyter Oldenbourg}, address = {M{\"u}nchen}, issn = {1433-7266}, doi = {10.1524/ncrs.2013.0123}, pages = {241 -- 242}, year = {2013}, abstract = {C19H18N2O12, orthorhombic, P2(1)2(1)2(1) (no. 19), a = 6.2472(6) angstrom, b = 17.576(2) angstrom, c = 18.848(3) angstrom, V = 2069.6 angstrom(3), Z = 4, R-gt(F) = 0.0393, wR(ref)(F-2) = 0.0694, T = 210 K.}, language = {en} } @article{LinkerBramborgKellingetal.2013, author = {Linker, Torsten and Bramborg, Andrea and Kelling, Alexandra and Schilde, Uwe}, title = {Crystal structure of trans-1,4-di-(2-(allyloxyethyl)-cyclohexa-2,5-diene-1,4-dicarboxylic acid, C18H24O6}, series = {Zeitschrift f{\"u}r Kristallographie : international journal for structural, physical and chemical aspects of crystalline materials ; New crystal structures}, volume = {228}, journal = {Zeitschrift f{\"u}r Kristallographie : international journal for structural, physical and chemical aspects of crystalline materials ; New crystal structures}, number = {2}, publisher = {De Gruyter Oldenbourg}, address = {M{\"u}nchen}, issn = {1433-7266}, doi = {10.1524/ncrs.2013.0124}, pages = {243 -- 244}, year = {2013}, abstract = {C18H24O6, triclinic, P (1) over bar (no. 2), a = 5.726(1) angstrom, b = 8.845(2) angstrom, c = 9.557(2) angstrom, alpha = 105.27(1)degrees, beta = 102.76(1)degrees, gamma = 103.49(1)degrees, V = 433.0 angstrom(3), Z = 1, R-gt(F) = 0.0412, wR(ref)(F-2) = 0.1075, T = 210 K.}, language = {en} } @article{BaierKellingJackstelletal.2013, author = {Baier, Heiko and Kelling, Alexandra and Jackstell, Ralf and Holdt, Hans-J{\"u}rgen}, title = {Rhodium(I) and Silver(I) Complexes of 4,5-Dicyano-1,3-dimesityl- and 4,5-Dicyano-1,3-dineopentylimidazol-2-ylidene}, series = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie}, volume = {639}, journal = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie}, number = {10}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0044-2313}, doi = {10.1002/zaac.201300250}, pages = {1731 -- 1739}, year = {2013}, abstract = {The new N-heterocyclic carbene (NHC) precursors 4,5-dicyano-1, -dimesityl- (9) and 4, 5-dicyano-1, 3-dineopentyl-2-(pentafluorophenyl)imidazoline (14) were synthesized. 9 could be determined by X-ray crystallography. With the 2-pentafluorophenyl-substituted imidazolines 9 and 14, the [AgCl(NHC)], [RhCl(COD)(NHC)], and [RhCl(CO)(2)(NHC)] complexes [NHC = 4, 5-dicyano-1, 3-dimesitylimidazol-2-ylidene (3) and 4, 5-dicyano-1, 3-dineopentylimidazol-2-ylidene (4)] were obtained. Crystal structures of [AgCl(3)] (15), [RhCl(COD)(3)] (17), [RhCl(COD)(4)] (18), and [RhCl(CO)(2)(3)] (19) were solved and with the crystal data of 19, the percent buried volume (\%V-bur) of 31.8(+/- 0.1)\% was determined for NHC 3. Infrared spectra of the imidazolines 9 and 14 and of the complexes 15-20 were recorded and the CO stretching frequencies of complexes 19 and 20 were used to determine the 3 ( (-1)) and 4 ( (-1)), thus proving that 1, 3-substitution of maleonitrile-NHCs does not have a significant effect for the high -acceptor strength of these carbenes.}, language = {en} } @article{SchwarzeTraegerKellingetal.2013, author = {Schwarze, Thomas and Traeger, Juliane and Kelling, Alexandra and Schilde, Uwe and Holdt, Hans-J{\"u}rgen}, title = {Macrocyclic dithiomaleonitriles for an efficient PdCl2 coordination}, series = {Inorganica chimica acta : the international inorganic chemistry journal}, volume = {408}, journal = {Inorganica chimica acta : the international inorganic chemistry journal}, number = {2}, publisher = {Elsevier}, address = {Lausanne}, issn = {0020-1693}, doi = {10.1016/j.ica.2013.08.020}, pages = {53 -- 58}, year = {2013}, abstract = {We have synthesized a set of new unsaturated macrocyclic dithioethers with an increasing number of flexible methylene units 1-7 (Scheme 2) to investigate the correlation between the ring size of these ligands, the chelation effect and the consequences for an efficient PdCl2 coordination. The dithioethers 1-7 and the complex [PdCl2(4)]center dot CHCl3 were characterized by X-ray diffraction analysis. The crystal structures of 1-7 show that 2-7 are better preorganized chelating ligands for an exocyclic PdCl2 coordination than 1. The chelation effect of 1-7, the orientation of the sulfur atoms and the S center dot center dot center dot S donor distances, are influenced by the flexibility of the methylene units. In this series the unsaturated macrocyclic ligands 5 and 6 are the best chelating ligands for an efficient PdCl2 coordination. Comparative solvent extraction experiments with mn-12S(2)O(2) (mn = maleonitrile) reveal that the low interface activity of the new ligands reduces the extraction rate. However, a comparison with open-chain dithiomaleonitriles shows the impact of the macrocyclic effect of 4 and 5 on the extraction yield.}, language = {en} } @article{MondalDeyBaburinetal.2013, author = {Mondal, Suvendu Sekhar and Dey, Subarna and Baburin, Igor A. and Kelling, Alexandra and Schilde, Uwe and Seifert, Gotthard and Janiak, Christoph and Holdt, Hans-J{\"u}rgen}, title = {Syntheses of two imidazolate-4-amide-5-imidate linker-based hexagonal metal-organic frameworks with flexible ethoxy substituent}, series = {CrystEngComm}, volume = {15}, journal = {CrystEngComm}, number = {45}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1466-8033}, doi = {10.1039/c3ce41632a}, pages = {9394 -- 9399}, year = {2013}, abstract = {A rare example of in situ linker generation with the formation of soft porous Zn- and Co-MOFs (IFP-9 and -10, respectively) is reported. The flexible ethoxy groups of IFP-9 and -10 protrude into the 1D hexagonal channels. The gas-sorption behavior of both materials for H-2, CO2 and CH4 showed wide hysteretic isotherms, typical for MOFs having a flexible substituent which can give rise to a gate effect.}, language = {en} } @article{MondalBhuniaBaburinetal.2013, author = {Mondal, Suvendu Sekhar and Bhunia, Asamanjoy and Baburin, Igor A. and J{\"a}ger, Christian and Kelling, Alexandra and Schilde, Uwe and Seifert, Gotthard and Janiak, Christoph and Holdt, Hans-J{\"u}rgen}, title = {Gate effects in a hexagonal zinc-imidazolate-4-amide-5-imidate framework with flexible methoxy substituents and CO2 selectivity}, series = {Chemical communications}, volume = {49}, journal = {Chemical communications}, number = {69}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1359-7345}, doi = {10.1039/c3cc42156b}, pages = {7599 -- 7601}, year = {2013}, abstract = {A new imidazolate-4-amide-5-imidate based MOF, IFP-7, is generated, having flexible methoxy groups, which act as molecular gates for guest molecules. This allows highly selective CO2 sorption over N-2 and CH4 gases.}, language = {en} }