Fine Tuning the Hydrophobicity of a New Three-Dimensional Cu MOF through Single Crystal Coordinating Ligand Exchange Transformations.

The synthesis, characterization, and single-crystal-to-single-crystal (SCSC) exchange reactions of a new 3D Cu MOF based on 5-aminoisophthalic acid (HAIP), [Cu(μ-ΟΗ)(ΑΙΡ)(HΑΙΡ)]·6DMF·HO - ·6DMF·HO, are reported. It exhibits a 3D structure based on two [Cu(μ-OH)] butterfly-like secondary building units, differing in their peripheral ligation, bridged through HAIP/AIP ligands. This compound displays the capability to exchange the coordinating ligand(s) and/or guest solvent molecules through SCSC reactions.

Synthesis and Characterization of Ruthenium-Paraphenylene-Cyclopentadienyl Full-Sandwich Complexes: Cytotoxic Activity against A549 Lung Cancer Cell Line and DNA Binding Properties.

Novel full-sandwich (-Cp)-Ru-paraphenylene complexes with the general formula [(-Cp)Ru(-L)](PF) where n = 1-3 and L = biphenyl, -terphenyl and -quaterphenyl, were synthesized and characterized by means of spectroscopic and analytical techniques. The structures of the complexes [(-Cp)Ru(-biphenyl)](PF) (), [(-Cp)Ru(-terphenyl)](PF) () and [(-Cp)Ru(-terphenyl)](PF) () was determined by X-ray single crystal methods. The interaction of the complexes [(-Cp)Ru(-quaterphenyl)]Cl, ()Cl, and [(-Cp)Ru(-quaterphenyl)]Cl, ()Cl, with the DNA duplex d(5'-CGCGAATTCGCG-3') was studied using NMR techniques.

Dual-Emissive Rectangular Supramolecular Pt(II)--Biphenyl with 4,4'-Bipyridine Derivative Metallacycles: Stepwise Synthesis and Photophysical Properties.

Mixed-ligand tetranuclear supramolecular coordination complexes (SCCs) of Pt(II)--biphenyl and bridging ligands derivatives of 4,4'-bypiridine ()-(), were synthesized and characterized. The SCCs were synthesized stepwise, starting from the Pt--biphenyl -Pt core. The crystal structure of complex {[Pt(2,2'-bpy)](-bph)(-(4,4'-bpy)}{PF} (2,2'-bpy = 2,2'-bipyridine, bph = -biphenyl and 4,4'-bpy = 4,4' bipyridine), was determined using single-crystal diffraction methods.

Synthesis, characterization, interactions with the DNA duplex dodecamer d(5'-CGCGAATTCGCG-3') and cytotoxicity of binuclear η-arene-Ru(II) complexes.

The novel binuclear η-arene-Ru(II) complexes with the general formula {[(η-cym)Ru(L)](μ-BL)}(PF), and their corresponding water soluble {[(η-cym)Ru(L)](μ-BL)}Cl, where cym = -cymene, L = 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen), BL = 4,4'-bipyridine (BL-1), 1,2-bis(4-pyridyl)ethane (BL-2) and 1,3-bis(4-pyridyl)propane (BL-3), were synthesized and characterized. The structure of {[(η-cym)Ru(phen)](μ-BL-1)}(PF) was determined by X-ray single crystal methods. The interaction of {[(η-cym)Ru(phen)](μ-BL-)}Cl ( = 1, 2, 3; (4), (5) and (6) correspondingly) with the DNA duplex d(5'-CGCGAATTCGCG-3') was studied by means of NMR techniques and fluorescence titrations.

Stepwise synthesis, characterization, DNA binding properties and cytotoxicity of diruthenium oligopyridine compounds conjugated with peptides.

Although the interactions of oligopyridine ruthenium complexes with DNA have been widely studied, the biological activity of similar diruthenium oligopyridine complexes conjugated with peptides has not been investigated. Herein, we report the stepwise synthesis and characterization of diruthenium complexes with the general formula [(L)Ru(tppz)Ru(L)] (tppz = 2,3,5,6-tetra(2-pyridyl)pyrazine, L = 2,2':6',2''-terpyridine or 4-phenyl-2,2':6',2''-terpyridine and L = 2,2':6',2''-terpyridine-4'-CO(Gly-Gly-Gly-LysCONH) (5), (6), n = 5; 2,2':6',2''-terpyridine-4'-CO(Gly-Gly-Lys-LysCONH) (7), (8), n = 6; 2,2':6',2''-terpyridine-4'-CO(Ahx-LysLysCONH) (9), (10), n = 5, Ahx = 6-aminohexanoic acid). The compounds [(trpy)Ru(tppz)Ru(trpy-COH)](PF), (2)(PF), [(ptrpy)Ru(tppz)Ru(trpy-COH)](PF), (3)(PF) and [(ptrpy)Ru(tppz)Ru(trpy)](PF), (4)(PF) were also characterized by single crystal X-ray methods.

Synthesis, reactivity and characterization of Pt(ii) complexes with N,N' chelating ligands; structure and dimethylsulfoxide reactivity relationship.

Platinum(ii) complexes of the formula PtLCl [L = 2-(2'-pyridyl)quinoxaline, (pqx) (1), 2,(2'-pyridyl)benzo[g]quinoxaline, (pbqx) (3) and 2,(2'-pyridyl)quinoline, (pqn) (5)] were synthesized and characterized by spectroscopic and X-ray diffraction methods. Also, monodentate coordination of the ligands pqx and pbqx formed the complexes trans-Pt(DMSO)pqxCl (2) and trans-Pt(DMSO)pbqxCl (4) as it is indicated from X-ray crystal structure and NMR studies. The reaction of the complexes (1), (3) and (5) with DMSO-d revealed a ligand-release solvolysis, which was studied by means of NMR techniques.

Interactions of Trivalent Lanthanide Cations with a New Hexadentate Di-Schiff Base: New Lanthanide(III) Complexes from (NE,N'E)-2,2'-(ethane-1,2-diylbis(oxy))bis(N-(pyridin-2-ylmethylene)ethanamine).

The novel lanthanide(III) complexes [Ln(NO(3))(2)L](NO(3)).3MeOH (Ln = La 1, Pr 2) and [Ln(NO(3))(3)L](NO(3)).2MeOH (Ln = Gd 3, Yb 4), where L = (NE,N'E)-2,2'-(ethane-1,2-diylbis(oxy))bis(N-(pyridin-2-ylmethylene)ethanamine), have been obtained by direct reaction of the Schiff base ligand and the corresponding hydrated lanthanide(III) nitrates in methanol.

Interactions of Zn(II) ions with three His-containing peptide models of histone H2A.

The interactions of Zn(ll) ions with the blocked hexapeptide models -TESHHK-, -TASHHK- and -TEAHHK- of the -ESHH- motif of the C-terminal of historic H2A were studied by using potentiometric and IH-NMR techniques. The first step of these studies was to compare the pKa values of the two His residues inside each hexapeptide calculated by potentiometric or H-NMR titrations. Hereafter, the potentiometric titrations in the pH range 5 11 suggest the formation of several monomeric Zn(ll) complexes.

Interpenetrated networks from a novel nanometer-sized pseudopeptidic ligand, bridging water, and transition metal ions with cds topology.

The combination of a new pseudopeptidic ligand, transition metal ions, and bridging water molecules results in the formation of [M(mu-TBG)(mu-H2O)(H2O)2].2H2O (M: Cu, Co and H2TBG: terephthaloylbisglycine); both compounds show rare two-fold interpenetrated three-dimensional cds-nets and reversible loss of coordinated and lattice water molecules.

An extremely stable Ni(II) complex derived from the hydrolytic cleavage of the C-terminal tail of histone H2A.

The C-terminal blocked tetrapeptides SHHK- and SAHK-, which represent the fragments produced from the hydrolysis of the hexapeptides' -TASHHK-, -TESHHK-, and -TESAHK- complexes with Ni(II), were synthesized and their interactions with Ni(II) ions were studied potentiometrically and spectroscopically. Both tetrapeptides interact strongly with Ni(II) ions leading to square-planar complexes with 4N {NH(2),2N(-),N(im)} coordination. The stability of the Ni-SHHK- complex is about 2 orders of magnitude higher than the Ni-SAHK- complex.

Interactions of Ni(II) and Cu(II) ions with the hydrolysis products of the C-terminal -ESHH- motif of histone H2A model peptides. Association of the stability of the complexes formed with the cleavage of the -E-S- bond.

We studied the interactions of Ni(II) and Cu(II) ions with the synthetic tetrapeptides SHHK- and SAHK-, which were blocked by amidation making them more realistic models of the hydrolysis peptidic products of the hexapeptides models of H2A histone. A combination of potentiometric and spectroscopic techniques (UV/Vis, CD, NMR and EPR) suggested that at pH > 7 both tetrapeptides coordinated equatorially through the imidazole ring of His in position 3, the N-terminal amino group and the two amide nitrogens existing between these groups {NH2, 2N-, NIm} forming 4N square-planar complexes. While in the case of the CuH(-1)L complex with SHHK- a possible axial coordination of the imidazole ring of His in position 2 was suggested, in the case of the analogous NiH(-1)L complex a completely different interaction of the same ring with metal ions was observed.