Piotr Smoleński

Cu(I) Complexes Bearing the New Sterically Demanding and Coordination Flexible Tris(3-phenyl-1-pyrazolyl)methanesulfonate Ligand and the Water-Soluble Phosphine 1,3,5-Triaza-7-phosphaadamantane or Related Ligands

The new sterically hindered scorpionate tris(3-phenylpyrazolyl)methanesulfonate (Tpms(Ph))(-) has been synthesized and its coordination behavior toward a Cu(I) center, in the presence of 1,3,5-triaza-7-phosphaadamantane (PTA), N-methyl-1,3,5-triaza-7-phosphaadamantane tetraphenylborate ((mPTA)[BPh4]) or hexamethylenetetramine (HMT) has been studied. The reaction between Li(Tpms(Ph)) (1) and [Cu(MeCN)4][PF6] yields [Cu(Tpms(Ph))(MeCN)] (2) which, upon further acetonitrile displacement on reaction with PTA, HMT, or (mPTA)[BPh4], gives the corresponding complexes [Cu(Tpms(Ph))(PTA)] (3), [Cu(Tpms(Ph))(HMT)] (4), and [Cu(Tpms(Ph))(mPTA)][PF6] (5). All the compounds have been characterized by (1)H, (31)P, (13)C, COSY or HMQC-NMR, IR, elemental analysis, and single crystal X-ray diffraction. In the complexes (3) and (5), which bear a phosphine ligand (i.e., PTA and mPTA, respectively), the new scorpionate ligand shows the typical N, N, N-coordination mode, whereas in (2) and (4), bearing a N-donor ligand (i.e., MeCN and HMT, respectively), it binds the metal via the N,N,O chelating mode, involving the sulfonate moiety.

Synthesis, Antimicrobial and Antiproliferative Activity of Novel Silver(I) Tris(pyrazolyl)methanesulfonate and 1,3,5-Triaza-7-phosphadamantane Complexes

Five new silver(I) complexes of formulas [Ag(Tpms)] (1), [Ag(Tpms)(PPh(3))] (2), [Ag(Tpms)(PCy(3))] (3), [Ag(PTA)][BF(4)] (4), and [Ag(Tpms)(PTA)] (5) {Tpms = tris(pyrazol-1-yl)methanesulfonate, PPh(3) = triphenylphosphane, PCy(3) = tricyclohexylphosphane, PTA = 1,3,5-triaza-7-phosphaadamantane} have been synthesized and fully characterized by elemental analyses, (1)H, (13)C, and (31)P NMR, electrospray ionization mass spectrometry (ESI-MS), and IR spectroscopic techniques. The single crystal X-ray diffraction study of 3 shows the Tpms ligand acting in the N(3)-facially coordinating mode, while in 2 and 5 a N(2)O-coordination is found, with the SO(3) group bonded to silver and a pendant free pyrazolyl ring. Features of the tilting in the coordinated pyrazolyl rings in these cases suggest that this inequivalence is related with the cone angles of the phosphanes. A detailed study of antimycobacterial and antiproliferative properties of all compounds has been carried out. They were screened for their in vitro antimicrobial activities against the standard strains Enterococcus faecalis (ATCC 29922), Staphylococcus aureus (ATCC 25923), Streptococcus pneumoniae (ATCC 49619), Streptococcus pyogenes (SF37), Streptococcus sanguinis (SK36), Streptococcus mutans (UA159), Escherichia coli (ATCC 25922), and the fungus Candida albicans (ATCC 24443). Complexes 1-5 have been found to display effective antimicrobial activity against the series of bacteria and fungi, and some of them are potential candidates for antiseptic or disinfectant drugs. Interaction of Ag complexes with deoxyribonucleic acid (DNA) has been studied by fluorescence spectroscopic techniques, using ethidium bromide (EB) as a fluorescence probe of DNA. The decrease in the fluorescence of DNA-EB system on addition of Ag complexes shows that the fluorescence quenching of DNA-EB complex occurs and compound 3 is particularly active. Complexes 1-5 exhibit pronounced antiproliferative activity against human malignant melanoma (A375) with an activity often higher than that of AgNO(3), which has been used as a control, following the same order of activity inhibition on DNA, i.e., 3 > 2 > 1 > 5 > AgNO(3)≫ 4.

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.

Oxorhenium Complexes Bearing the Water-Soluble Tris(pyrazol-1-yl)methanesulfonate, 1,3,5-Triaza-7-phosphaadamantane, or Related Ligands, as Catalysts for Baeyer–Villiger Oxidation of Ketones

New rhenium(VII or III) complexes [ReO3(PTA)2][ReO4] (1) (PTA = 1,3,5-triaza-7-phosphaadamantane), [ReO3(mPTA)][ReO4]I (2) (mPTA = N-methyl-1,3,5-triaza-7-phosphaadamantane cation), [ReO3(HMT)2][ReO4] (3) (HMT = hexamethylenetetramine), [ReO3(η(2)-Tpm)(PTA)][ReO4] (4) [Tpm = hydrotris(pyrazol-1-yl)methane, HC(pz)3, pz = pyrazolyl], [ReO3(Hpz)(HMT)][ReO4] (5) (Hpz = pyrazole), [ReO(Tpms)(HMT)] (6) [Tpms = tris(pyrazol-1-yl)methanesulfonate, O3SC(pz)3(-)] and [ReCl2{N2C(O)Ph}(PTA)3] (7) have been prepared from the Re(VII) oxide Re2O7 (1-6) or, in the case of 7, by ligand exchange from the benzoyldiazenido complex [ReCl2{N2C(O)Ph}(Hpz)(PPh3)2], and characterized by IR and NMR spectroscopies, elemental analysis and electrochemical properties. Theoretical calculations at the density functional theory (DFT) level of theory indicated that the coordination of PTA to both Re(III) and Re(VII) centers by the P atom is preferable compared to the coordination by the N atom. This is interpreted in terms of the Re-PTA bond energy and hard-soft acid-base theory. The oxo-rhenium complexes 1-6 act as selective catalysts for the Baeyer-Villiger oxidation of cyclic and linear ketones (e.g., 2-methylcyclohexanone, 2-methylcyclopentanone, cyclohexanone, cyclopentanone, cyclobutanone, and 3,3-dimethyl-2-butanone or pinacolone) to the corresponding lactones or esters, in the presence of aqueous H2O2. The effects of a variety of factors are studied toward the optimization of the process.

Extending the coordination chemistry of 1,3,5-triaza-7-phosphaadamantane (PTA) to cobalt centers: first examples of co-PTA complexes and of a metal complex with the PTA oxide ligand.

Water-soluble Co (III) and Co (II) complexes with P- or N-coordinated PTA or PTA oxide ligands, respectively, have been prepared and fully characterized, constituting the first examples of cobalt compounds bearing PTA or any ligand with a cage-like PTA core, the latter complex providing also the first PTA oxide coordination to a metal center.

Bioactive Silver–Organic Networks Assembled from 1,3,5-Triaza-7-phosphaadamantane and Flexible Cyclohexanecarboxylate Blocks

Three novel bioactive silver-organic networks, namely, the 2D polymer [Ag(μ3-PTA)(chc)]n·n(Hchc)·2nH2O (1), the 3D bioMOF [Ag2(μ3-PTA)2(μ2-chdc)]n·5nH2O (2), and the 2D polymer [Ag2(μ2-PTA)2(μ4-H2chtc)]n·6nH2O (3), were constructed from 1,3,5-triaza-7-phosphaadamantane (PTA) and various flexible cyclohexanecarboxylic acids as building blocks {cyclohexanecarboxylic (Hchc), 1,4-cyclohexanedicarboxylic (H2chdc), and 1,2,4,5-cyclohexanetetracarboxylic (H4chtc) acid, respectively}. The obtained products 1-3 were fully characterized by IR and NMR spectroscopy, ESI-MS(±) spectrometry, elemental and thermogravimetric (TGA) analyses, and single-crystal and powder X-ray diffraction. Their structural diversity originates from distinct coordination modes of cyclohexanecarboxylate moieties as well as from the presence of unconventional N,N,P-tridentate or N,P-bidentate PTA spacers. Topological classification of underlying metal-organic networks was performed, disclosing the hcb, 4,4L28, and a rare fsc-3,4-Pbcn-3 topology in 1, 2, and 3, respectively. Moreover, combination of aqueous solubility (S25°C ≈ 4-6 mg mL(-1)), air stability, and appropriate coordination environments around silver centers favors a release of bioactive Ag(+) ions by 1-3, which thus act as potent antibacterial and antifungal agents against Gram-positive (S. aureus) and Gram-negative (E. coli and P. aeruginosa) bacteria as well as a yeast (C. albicans). The best normalized minimum inhibitory concentrations (normalized MIC) of 10-18 (for bacterial strains) or 57 nmol mL(-1) (for a yeast strain) were achieved. Detailed ESI-MS studies were performed, confirming the relative stability of 1-3 in solution and giving additional insight on the self-assembly formation of polycarboxylate Ag-PTA derivatives and their crystal growth process.

Water-soluble and stable dinitrogen phosphine complexes trans-[ReCl(N2)(PTA-H)n(PTA)4−n]n+ (n = 0–4), the first with 1,3,5-triaza-7-phosphaadamantane

The first dinitrogen complexes with the hydrosoluble PTA ligand, or its protonated form PTA-H, trans-[ReCl(N2)(PTA-H)n(PTA)(4-n)]n+ (n = 0-4), are prepared, shown to be soluble and stable in water, interconvertible by stepwise protonation/deprotonation and to form, upon N2 loss, the corresponding penta-coordinate compounds. Dinitrogen displacement by CO affords trans-[ReCl(CO)(PTA)4].

Silver(I) 1,3,5-Triaza-7-phosphaadamantane Coordination Polymers Driven by Substituted Glutarate and Malonate Building Blocks: Self-Assembly Synthesis, Structural Features, and Antimicrobial Properties

Three new bioactive silver(I) coordination polymers formulated as [Ag2(μ2-PTA)(μ3-PTA)(μ2-pga)(H2O)]n·6H2O (1), [Ag2(μ2-PTA)(μ3-PTA)(Hpmal)2]n·2H2O (2), and [Ag(μ3-PTA) (Hdmga)]n (3) were self-assembled from Ag2O, 1,3,5-triaza-7-phosphaadamantane (PTA), and a substituted dicarboxylic acid (3-phenylglutaric acid (H2pga), phenylmalonic acid (H2pmal), or 3,3-dimethylglutaric acid (H2dmga)) as an ancillary ligand. Compounds 1-3 were fully characterized by IR and NMR spectroscopy, ESI-MS(±), elemental analysis, and single-crystal X-ray diffraction, revealing that their architectural and topological diversity is governed by structural modulation of a dicarboxylate building block. The structures vary from a 1D cyclic chain with the SP 1-periodic net (4,4)(0,2) topology in 2 to distinct 2D metal-organic layers with the cem-d and hcb topologies in 1 and 3, respectively. In addition, compounds 1-3 exhibit a notable antimicrobial efficiency against a panel of common Gram-negative (E. coli and P. aeruginosa) and Gram-positive (S. aureus) bacteria and yeast (C. albicans). The best normalized minimum inhibitory concentrations (normalized MIC) of 11-23 nmol mL(-1) (for bacterial strains) or 68 nmol mL(-1) (for a yeast strain) are shown by compound 2, and the eventual structure-bioactivity correlations are discussed.

New silver BioMOFs driven by 1,3,5-triaza-7-phosphaadamantane-7-sulfide (PTAS): synthesis, topological analysis and antimicrobial activity

Two new bioactive silver–organic frameworks [Ag(μ3-PTAS)]n(NO3)n·nH2O (1) and [Ag4(μ4-PTAS)(μ5-PTAS)(μ2-SO4)2(H2O)2]n·2nH2O (2) were easily assembled, thus opening up the application of PTAS as a versatile N,S-building block in the crystal engineering of MOFs. The obtained products reveal infinite 3D networks driven by multiply bridging PTAS spacers that adopt unprecedented N2S-coordination modes. The topological analysis of 1 discloses an uninodal 3-connected net with the srs (SrSi2) topology, whereas 2 features a pentanodal 3,4,5-connected net with a hitherto undocumented topology. Apart from representing the first MOFs derived from PTAS, the compounds 1 and 2 display notable antibacterial and antifungal activities.

New water-soluble rhodium(I) complexes containing 1-methyl-1-azonia-3,5-diaza-7-phosphaadamantane iodide

Reaction of [Rh2Cl2(CO)4] with stoichiometric quantities of 1-methyl-1-azonia-3,5-diaza-7-phosphaadamantane iodide (mtpa+I-) in MeOH and H2O yields square-planar [RhI(CO)(mtpa+I-)2] 1 and trigonal-bipyramidal [RhI(CO)(mtpa+I-)3]·4H2O 2, respectively. The complexes are stable in aqueous solution under inert atmosphere and catalyse the hydroformylation and the hydrocarboxylation of alkenes and the hydrogenation of aldehydes and alkenes. An X-ray crystallography study revealed that 2 has a TBPY-5 structure. The coordination around the Rh atom forms a nearly ideal trigonal bipyramid [a=15.705(3) A, b=13.219(3) A, c=20.894(4) A, monoclinic, space group P21/c, Z=4, β=110.72(3)°].