TY - JOUR A1 - Schulz, Ellina A1 - Mawamba, Viviane A1 - Löhr, Mario A1 - Hagemann, Carsten A1 - Friedrich, Alexandra A1 - Schatzschneider, Ulrich T1 - Structure–activity relations of Pd(II) and Pt(II) thiosemicarbazone complexes on different human glioblastoma cell lines JF - Zeitschrift für Anorganische und Allgemeine Chemie N2 - Ten thiosemicarbazone ligands obtained by condensation of pyridine-2-carbaldehyde, quinoline-2-carbaldehyde, 2-acetylpyridine, 2-acetylquinoline, or corresponding 2-pyridyl ketones with thiosemicarbazides RNHC(S)NHNH\(_{2}\) and R=CH\(_{3}\), C\(_{6}\)H\(_{5}\) were prepared in good yield. The reaction of [PdCl\(_{2}\)(cod)] with cod=1,5-cyclooctadiene or K\(_{2}\)[PtCl\(_{4}\)] resulted in a total of 17 Pd(II) and Pt(II) complexes isolated in excellent purity, as demonstrated by \(^{1}\)H, \(^{13}\)C, and, where applicable, \(^{195\)Pt NMR spectroscopy combined with CHNS analysis. The cytotoxicity of the title compounds was studied on four human glioblastoma cell lines (GaMG, U87, U138, and U343). The most active compound, with a Pd(II) metal centre, a 2-quinolinyl ring, and methyl groups on both the proximal C and distal N atoms exhibited an EC\(_{50}\) value of 2.1 μM on the GaMG cell lines, thus being slightly more active than cisplatin (EC\(_{50}\) 3.4 μM) and significantly more potent than temozolomide (EC\(_{50}\) 67.1 μM). Surprisingly, the EC\(_{50}\) values were inversely correlated with the lipophilicity, as determined with the “shake-flask method”, and decreased with the length of the alkyl substituents (C\(_{1}\)>C\(_{8}\)>C\(_{10}\)). Correlation with the different structural motifs showed that for the most promising anticancer activity, a maximum of two aromatic rings (either quinolinyl or pyridyl plus phenyl) combined with one methyl group are favoured and the Pd(II) complexes are slightly more potent than their Pt(II) analogues. KW - glioblastoma KW - platinum KW - palladium KW - thiosemicarbazone KW - anticancer activity Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318281 SN - 0044-2313 VL - 648 IS - 12 ER - TY - JOUR A1 - Brunecker, Carina A1 - Müssig, Jonas H. A1 - Arrowsmith, Merle A1 - Fantuzzi, Felipe A1 - Stoy, Andreas A1 - Böhnke, Julian A1 - Hofmann, Alexander A1 - Bertermann, Rüdiger A1 - Engels, Bernd A1 - Braunschweig, Holger T1 - Boranediyl‐ and Diborane(4)‐1,2‐diyl‐Bridged Platinum A‐Frame Complexes JF - Chemistry – A European Journal N2 - Diplatinum A‐frame complexes with a bridging (di)boron unit in the apex position were synthesized in a single step by the double oxidative addition of dihalo(di)borane precursors at a bis(diphosphine)‐bridged Pt\(^{0}\)\(_{2}\) complex. While structurally analogous to well‐known μ‐borylene complexes, in which delocalized dative three‐center‐two‐electron M‐B‐M bonding prevails, theoretical investigations into the nature of Pt−B bonding in these A‐frame complexes show them to be rare dimetalla(di)boranes displaying two electron‐sharing Pt−B σ‐bonds. This is experimentally reflected in the low kinetic stability of these compounds, which are prone to loss of the (di)boron bridgehead unit. KW - boron KW - bonding KW - EDA-NOCV KW - oxidative addition KW - platinum Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214707 VL - 26 IS - 39 SP - 8518 EP - 8523 ER - TY - JOUR A1 - Braunschweig, Holger A1 - Kramer, T. T1 - Crystal structure of μ-1κC:2(\(η^2\))-carbonyl-carbonyl-1κC-chlorido-2κCl-μ-chloridoborylene-1:2\(κ^2\) B:B-[1(\(η^5\))-pentamethylcyclopentadienyl](tricyclohexylphosphane-2κP)iron(II)platinum(II) benzene monosolvate N2 - In the mol­ecular structure of the dinuclear title compound \([η^5-(C_5(CH_3)_5)(CO)Fe{(μ-BCl)(μ-CO)}PtCl(P(C_6H_{11})_3)]·C_6H_6\), the two metal atoms, iron(II) and platinum(II), are bridged by one carbonyl (μ-CO) and one chlorido­borylene ligand (μ-BCl). The \(Pt^{II}\) atom is additionally bound to a chloride ligand situated trans to the bridging borylene, and a tri­cyclo­hexyl­phosphane ligand \((PCy_3)\) trans to the carbonyl ligand, forming a distorted square-planar structural motif at the \(Pt^{II}\) atom. The \(Fe_{II}\) atom is bound to a penta­methyl­cyclo­penta­dienyl ligand \([η^5-C_5(CH_3)_5]\) and one carbonyl ligand (CO), forming a piano-stool structure. Additionally, one benzene solvent mol­ecule is incorporated into the crystal structure, positioned staggered relative to the penta­methyl­cyclo­penta­dienyl ligand at the \(Fe^{II}\) atom, with a centroid–centroid separation of 3.630 (2) Å. KW - platinum KW - oxidative addition KW - borylene KW - heterodinuclear compound KW - crystal structure Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120120 VL - 70 IS - 11 ER -