Florian P. Pruchnik

Structure, properties and cytostatic activity of tributyltin aminoarylcarboxylates

Abstract Properties of butyltin complexes [Sn(C4H9-n)3{OOCC6H3(NH2)2-3,4}]n (1), [Sn(C4H9-n)3{OOCC6H3(NH2)2-3,5}] (2), [Sn(C4H9-n)3{OOCC6H4NNC6H4N(CH3)2-4}] (3) and [Sn(C6H5)3{OOCC6H3(NH2)2-3,5}]n (4) have been investigated. 1H, 13C and 119Sn NMR spectra indicate that the compounds in chloroform are distorted tetrahedral and in strongly coordinating solvents trigonal-bipyramidal complexes. Structure of complex 3 has been determined by X-ray crystallography. This compound adopts trigonal bipyramidal structure with bridging carboxylato ligand bound asymmetrically with tin atoms in axial positions. The complexes are effective cytostatic agents.

Rhodium(III) complexes with polypyridyls and pyrazole and their antitumor activity

Abstract Synthesis and properties of rhodium complexes with nitrogen ligands [RhCl 2 (Hpz) 4 ][RhCl 4 (Hpz) 2 ] ( 1 ), [RhCl 3 (tpy)] ( 2 ), [RhCl 3 (tpta)]·H 2 O ( 3 ) and [Rh(tpy) 2 (Him)]Cl 3 ·3H 2 O ( 4 ), have been described. X-ray structures of complexes 1 – 3 have been determined. IR, UV–Vis and 1 H NMR spectra of the complexes have been discussed. Cytostatic activity of the complexes against HCV29T tumor cells increases in the series: 1 3 2 4 . The cytostatic activity of complex 4 is greater than that of cisplatin. Interaction of the complexes with DNA has been investigated.

RHODIUM(I) ACETYLACETONATO COMPLEXES WITH FUNCTIONALIZED PHOSPHINES

Abstract Rhodium(I) complexes [Rh(acac)(CO)(PR3)] with 1,3,5-triaza-7-phosphatricyclo[3.3.1.13,7]decane (tpa), tris(2-cyanoethyl)phosphine (cyep), tris(3-sodium sulfonatophenyl)phosphine (tppts), tris(o-methoxyphenyl)phosphine (ompp), tris(p-methoxyphenyl)phosphine (pmpp), tris(2,4,6-trimethoxyphenyl)phosphine (tmpp), PPh2(pyl), PPh(pyl)2 and P(pyl)3 (pyl=2-pyridyl) have been synthesized and characterized with 1H- and 31P-NMR and IR spectra. The measured 31P coordination chemical shifts, Δδ31P{1H}, correlate well with ν(CO). Differences in 1H chemical shifts of methyl groups of acac ligand, ΔδMe, depend both on steric and electronic properties of phosphine ligand. Thus ΔδMe increases with decrease of Δδ31P{1H} and increases with increase of the cone angle of phosphine. Catalytic activity of complexes with tpa, cyep and tppts has been investigated. They are efficient catalysts for hydrogenation of C C and C O bonds, isomerization of alkenes and hydroformylation of alkenes. The mechanism of isomerization of allyl alcohol to propanal has been elucidated.

Rhodium wires based on binuclear acetate-bridged complexes

Abstract The synthesis, properties, structure and conductivity of a new class of one-dimensional, mixed valence Rh(I)–Rh(II) complexes { Rh 2 ( μ-O 2 CMe ) 2 ( N – N ) 2 ][ BX 4 ]} n ( N – N =bipyridine, phenanthroline; X=F, Ph) are described.

PROPERTIES OF RHODIUM(II) COMPLEXES HAVING CYTOSTATIC ACTIVITY

Dimeric rhodium (II) carboxylate complexes [Rh2(OOCR)4L2], [Rh2(OOCR)2(NN)2L2]2+ and [Rh2Cl2(RCOO)2(NN)2] (R  PhCH(OH), MeCH(OH), HOOCCH(OH)CH(OH), Me; NN  2,2′-bipyridine, 1,10-phenanthroline) have been synthesized and characterized using electronic, NMR, and IR spectra. Cytostatic activity of these complexes has been tested for human oral carcinoma KB cell line. Some complexes with hydroxycarboxylates and [Rh2(RCOO)2(NN)2]2+ compounds show higher cytostatic activity than [Rh2(OOCCH3)4(H2O)2].

Studies on the interaction between human serum albumin and [Rh2(OAc)2(bpy)2(H2O)2](OAc)2

Absorption, CD, fluorescence, and ICP(AES) methods were used to evaluate the interaction of [Rh2(OAc)2(bpy)2(H2O)2](OAc)2 with human serum albumin (HSA). The rhodium complex reacts easily with HSA; the Rh atoms are coordinated to protein via the imidazole rings of His residues. When the protein was incubated for 24 h at 37 degrees C, the amount of rhodium was found to be approximately 7 mol per mol of HSA. Analysis of CD spectra showed the decreasing helix content to be about 15% in the metal-bound HSA. The relative fluorescence intensity of HSA bound with rhodium decreased to 20% of that of the native state, suggesting that perturbation around the Trp-214 residue took place. This was confirmed by the destruction of the warfarin binding site. The rhodium binding weakens the interaction of HSA with other molecules like heme or bilirubin.

The structure of oxotricobalt acetate

Abstract The product of the oxidation reaction of cobalt(II) acetate in anhydrous acetic acid solution has been investigated. The IR, UV and visible spectra as well as magnetic susceptibility measurements on cobalt complex are discussed. According to those and polarographic and conductometric studies, the complex investigated has been reformulated as Co3O(OAc)6(HOAc)3.

Structure, Properties and Cytostatic Activity of Triorganotin (Aminoaryl)carboxylates

The properties of vinyltin and phenyltin complexes [Sn(CH=CH2)3{μ-OOCC6H3(NH2)2-3,4}]n (1), [Sn(C6H5)3{OOCC6H3(NH2)2-3,4}] (2), [Sn(C6H5)3{OOC-2-C6H4N=NC6H4N(CH3)2-4}] (3) and [Sn(CH=CH2)3{OOC-2-C6H4N=NC6H4N(CH3)2-4}] (4) have been investigated. The structures of complexes 1, 2, and 3, have been determined by X-ray crystallography. Compound 1 is a distorted trigonal-bipyramidal complex and compounds 2 and 3 adopt a distorted tetrahedral structure. Complex 1 is a single-strand polymer with a bridging 3,4-diaminobenzoato ligand coordinating via the O(1) atom of the carboxylato group and the nitrogen atom of the para-amino group. The oxygen and nitrogen atoms occupy the axial coordination sites. The Sn(1)−N(2A) bond is weak. In complexes 2 and 3 the carboxylato ligands are strongly coordinated to the central atom via one oxygen atom, and the Sn(1)−O(2) distances are considerably longer. Weak interactions of the central atom with the amino group in complex 1, and with the O(2) atoms in complexes 2 and 3, as well as the hydrogen bonds, stabilize the crystal structure. The complexes are effective cytostatic agents. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Interaction of tetra-μ-acetatodirhodium(II) with human serum albumin

The interaction of Rh2(OAc)4 with human serum albumin (HSA) has been studied by absorption difference spectroscopy, CD spectroscopy, and quantitative precipitating HSA-antibody test. Our results demonstrate that this rhodium complex reacts easily with HSA at several ratios of reagents. The Rh atoms are coordinated to protein molecules via the imidazole rings of His residues. The structural studies have shown the conformational change of HSA modified by rhodium. Rhodium binding lowers the helicity of the native protein between 8 to 18% depending upon the molar ratios (from 1:1 to 10:1). Denaturation measurements of free HSA and HSA in the presence of dirhodium(II) acetate complex with 8-M urea followed by CD spectroscopy, suggest that rhodium affects the secondary protein structure and might stabilize HSA against denaturing agents. 8-M urea caused the unfolding of the native HSA secondary structure by about 40% and the structure of Rh(OAc)4-HSA by about 10%. The modification of native HSA by rhodium causes its decreased ability to precipitate with HSA antibodies. The decrease of antigenic properties can be connected with the unfolding of the antigen structure, which brings about perturbation of complementarity of the antigen-antibody reactive sites.

Properties of Binuclear Rhodium(II) Complexes and Their Antibacterial Activity.

Binuclear rhodium(II) complexes [Rh2Cl2(μ-OOCR)2(N-N)2], [Rh2(μ-OOCR)2(N-N)2(H2O)2](RCOO)2 and [Rh2Cl2(μ-OOCCH3)(terpy)2](H3O)Cl2.9H2O (R = H, Me, Bun, ph, PhCHOH; N-N = 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (dmp) and 6,7-dimethyl-2,3- di(2-pyridyl)quinoxaline (dmpq); terpy 2,2′:6′,2′′-terpyridine) have been synthesized and their structure and properties have been studied by electronic, IR and 1H NMR spectroscopy. Antibacterial activity of these complexes against Staphylococcus aureus and Escherichia coli has been investigated. The most active antibacterial agents against S. aureus were [Rh2(OOCPh)2(phen)2(H2O)2]2+, [Rh2(OOCPh)2(dmpq)2(H2O)2]2+, [Rh2(OOCBu)2(phen)2(H2O)2]2+ and [Rh2-(OOCBu)2(bpy)2(H2O)2]2+ which were considerably more active than the appropriate nitrogen ligands. The complexes show rather low activity against E. coli.