Synthesis, characterization and photophysics of alkyne bridged bimetallic rhenium(I) and ruthenium(II) complexes

Six new homobimetallic and heterobimetallic complexes of rhenium(I) and ruthenium(II) bridged by ethynylene spacer [(CO)₃(bpy)Re(BL)Re(bpy)(CO)₃]²⁺ [Cl(bpy)₂Ru(BL)Ru(bpy)₂Cl]²⁺ and [(CO)₃(bpy)Re(BL)Ru(bpy)₂Cl]²⁺ (bpy = 2,2′-bipyridine, BL = 1,2-bis(4-pyridyl)acetylene (bpa) and 1,4-bis(4-pyridyl)butadiyne (bpb) are synthesized and characterized. The electrochemical and photophysical properties of all the complexes show a weak interaction between two metal centers in heterobimetallic complexes. The excited state lifetime of the complexes is increased upon introduction of ethynylene spacer and the transient spectra show that this is due to delocalization of electron in the bridging ligand. Also, intramolecular energy transfer from *Re(I) to Ru(II) in Re–Ru heterobimetallic complexes occurs with a rate constant 4 × 10⁷ s⁻¹.     

Copper(II), palladium(II) and platinum(II) chloride complexes with 5-amino-2-tert-butyltetrazole: Synthesis, characterization and cytotoxicity

Complexes CuL₃Cl₂, PdL₂Cl₂ and PtL₂Cl₂, where L is a novel ligand from the series of 2-substituted 5-aminotetrazoles, namely 5-amino-2-tert-butyltetrazole (1), have been synthesized by the reaction of metal(II) chlorides with 1 and characterized by IR spectroscopy, thermal and X-ray analyses. The crystallographic structural analysis of these complexes revealed that 1 acts as a monodentate ligand coordinated to the metal via endocyclic N4 atom. Platinum complex demonstrates promising cytotoxicity against human cervical carcinoma cells with IC₅₀ value average between those of cisplatin and carboplatin.     

Synthesis and structural characterization of two cationic dinuclear cymene-ruthenium(II) complexes with thiolato and chloro bridges

Treatment of [(p-cymene)RuCl₂]₂ with HSp-Tol or HSCH₂Ph in the presence of K[PF₆] gave the cationic dinuclear cymene–ruthenium(II) complexes [(p-cymene)₂Ru₂(μ-Cl)(μ-Sp-Tol)₂][PF₆] (1) and [(p-cymene)₂Ru₂(μ-Cl)(μ-SCH₂Ph)₂][PF₆] (2), respectively, which have been characterized by IR, NMR spectroscopies and mass spectrometry along with microanalyses. Their crystal structures were determined by single-crystal X-ray diffraction analyses. The structures of the cationic complexes contain the unusual pseudo-trigonal-bipyramidal Ru₂S₂Cl framework without a ruthenium–ruthenium single bond. The two p-cymene–ruthenium units are held together by two bridging thiolates and one bridging chloride.     

Synthesis, characterization, structures and cytotoxic activity of palladium(II) and platinum(II) complexes containing bis(2-pyridylmethyl)amine and saccharinate

New palladium(II) and platinum(II) complexes containing bis(2-pyridylmethyl)amine (bpma) and saccharinate (sac), [Pd(bpma)(sac)](sac)·2H₂O (1), [Pt(bpma)(sac)](sac)·2H₂O (2), [Pd(bpma)Cl](sac)·2H₂O (3) and [Pt(bpma)(sac)]Cl·1.5H₂O (4), were synthesized and characterized by elemental analysis, IR, NMR and TG-DTA. A single-crystal X-ray analysis of 3 and 4 proved a distorted square-planar geometry around the metal ions with one tridentate bpma ligand and one Cl or sac monoanion. The [Pd(bpma)Cl]⁺ ions in 3 form dimers by intermolecular N-H?Cl and Pd?Pd interactions. The cations reside in the centers of a hydrogen-bonded honeycomb network formed by the uncoordinated sac ions and the lattice water molecules, while the cations of 4 are connected by N-H?Cl and OW-H?O hydrogen bonds into one-dimensional chains. Cyclic planar tetrameric and trimeric water clusters were observed in 3 and 4, respectively. Cytotoxicity of 1-4 was tested against A549, C6 and CHO cells. Although 2 and 4 have no cytotoxicity, the best results were achieved for 1 and 3. In particular, the cyctotoxic activity of 3 is comparable to cisplatin.     

Synthesis,characterization, and fluorescence properties of dinuclear cadmium(II) complexes

Four dinuclear cadmium(II) complexes, [Cd₂(L¹)(μ₂-Cl)Cl₂] (1), [Cd₂(L²)(μ₂-Cl)Cl₂] (2), [Cd₂(L³)(μ₂-Cl)Cl₂] (3), and [Cd₂(L⁴)₃ClO₄] (4), where HL¹ = 4-methyl-2,6-bis(1-(2-piperidinoethyl)iminomethyl)-phenol, HL² = 4-methyl-2,6-bis(1-(2-pyrrolidinoethyl)iminomethyl)-phenol, HL³ = 4-methyl-2,6-bis(1-(2-morpholinoethyl)iminomethyl)-phenol and HL⁴ = 4-methyl-2,6-bis(cyclohexylmethyl)iminomethyl)-phenol, were synthesized. They were characterized by elemental analysis, FT-IR, UV–Vis, fluorescence and electronspray ionization mass spectroscopy. Complexes 1 and 4 were also characterized by single crystal X-ray analysis. The cadmiums atoms in 1 are linked by μ₂-chloride in a distorted square pyramidal geometry, whereas cadmium atom in 4 is in a distorted octahedral environment. The complexes show emission bands around 500 nm with excitation at 395 nm.     

Synthesis and characterization of two Cu(II) complexes with a new pyrazole-based Schiff base ligand: crystallography,DNA interaction and antimicrobial activity of Ni(II) and Cu(II) complexes

Reaction of Cu(II) nitrate with a new pyrazole-based Schiff base ligand, 5-methyl-3-formylpyrazole-N-(2′-methylphenoxy)methyleneimine (MPzOA), afforded two types of Cu(II) complexes at different reaction temperatures, [Cu(MP_zOA)(NO₃)]₂ (1) and [Cu(3,7,11,15-tetramethylporphyrin)(H₂O)](NO₃)₂ (2), reported together with a Ni(II) complex, [Ni(MPzOA)₂(H₂O)₂]Br₂ (3). The compounds are characterized by single crystal X-ray structure analyses along with several physico-chemical and spectral parameters. Complex 1 is authenticated as a bis(μ-pyrazolato)dicopper(II), while 2 is a porphyrinogen and 3 is a distorted octahedral complex. Structural analyses of the complexes reveal that 1 crystallized in monoclinic P2₁/n space group while 2 and 3 crystallized in monoclinic C2/c space group. DNA-binding studies of the complexes have shown that the complexes interact with CT-DNA. DNA-cleavage studies with plasmid DNA have shown that 1 and 2 induce extensive DNA cleavage in the presence of H₂O₂ as an additive, whereas there is no change in degradation of super-coiled DNA by 3 in the presence of additive. The antimicrobial studies of the complexes against Escherichia coli DH5α bacteria strain indicated that all the complexes were capable of killing E. coli with different LD50 values.     

Synthesis and characterization of Ni(II), Pd(II) and Pt(II) complexes of 2,4-diamino-5-(3, 4, 5-trimethoxybenzyl)pyrimidine complexes

The Ni(II), Pd(II) and Pt(II) complexes of 2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine (trimethoprim) have been synthesized and characterized by elemental analysis, electronic and IR spectroscopy, and magnetic susceptibility measurements. The single-crystal X-ray structure of the Ni(II) complex is reported. Ni(II) is coordinated to the N(1) atoms of two trimethoprim molecules that act as monodentates. Octahedral coordination around the nickel atom is completed by coordination to two molecules of methanol and two acetate ions. Pd(II) and Pt(II) complexes are square planar and the metal ions coordinate one molecule of trimethoprim, two chloride ions and a molecule of water.     

Synthesis and crystal structure characterization of iron(II), cobalt(II) and nickel(II) complexes with 1,3-bis(2-pyridylmethylthio)propane

Three new mononuclear complexes of nitrogen–sulfur donor sets, formulated as [Fe^II(L)Cl₂] (1), [Co^II(L)Cl₂] (2) and [Ni^II(L)Cl₂] (3) where L = 1,3-bis(2-pyridylmethylthio)propane, were synthesized and isolated in their pure form. All the complexes were characterized by physicochemical and spectroscopic methods. The solid state structures of complexes 1 and 3 have been established by single crystal X-ray crystallography. The structural analysis evidences isomorphous crystals with the metal ion in a distorted octahedral geometry that comprises NSSN ligand donors with trans located pyridine rings and chlorides in cis positions. In dimethylformamide solution, the complexes were found to exhibit Fe^II/Fe^III, Co^II/Co^III and Ni^II/Ni^III quasi-reversible redox couples in cyclic voltammograms with E_1/2 values (versus Ag/AgCl at 298 K) of +0.295, +0.795 and +0.745 V for 1, 2 and 3, respectively.     

Synthesis, chemical characterization and preliminary in vitro antitumor activity evaluation of new ruthenium(II) complexes with sugar derivatives

Three new complexes of Ru(II), namely [RuCl₂(Glun-N,O)₂]Na₂ (I; Glun = glucosaminate), [RuCl₂(1-Tglu)(EtOH)₂]Na (II; 1-Tglu = 1-thio-β-d-glucose) and [Ru₂(EtOH)₆(AL)Cl₄] (III; AL = 6′-aminolactose) were prepared from the same Ru(II) precursor, [RuCl₂(DMSO)₄] (DMSO = dimethyl sulfoxide). The characterization of the complexes was carried out by elemental analysis, FT-IR, ES-MS, NMR, EXAFS and DFT calculations. The effectiveness of the complexes on metastatic melanoma A 375 was investigated. The results show that complex II is the most active species.     

Synthesis,spectroscopic characterization,and antimicrobial activities of Ni(II) and Fe(II) complexes with N-(2-hydroxyethyl)-5-nitrosalicylaldimine

Metal complexes [Ni(HL1)₂H₂O] (1) and [Fe(HL1)₂] (2), where HL1 is the tridentate Schiff base N-(2-hydroxyethyl)-5-nitrosalicylaldimine, were synthesized and characterized by spectroscopic methods. The crystal structures of 1 and 2 have been determined by single crystal diffraction at 100?K. Complexes 1 and 2 have a distorted octahedral geometry. The ligand and metal complexes were screened for antibacterial and antifungal activities by the disk diffusion, microdilution broth, and single spore culture techniques. Antimicrobial activities of the ligand and its complexes have been tested against 10 bacteria, two yeast, and five filamentous fungi. The ligand and metal complexes were found to be active against all tested micro-organisms.     

Synthesis,characterization, and DNA binding of ruthenium(II) complexes with 2-benzo[b] furan-2-yl-1H-imidazo[4,5f][1,10]phenanthroline as an intercalative ligand

DNA-binding properties of a number of ruthenium complexes with different polypyridine ligands are reported. The new polypyridine ligand BFIP (=2-benzo[b] furan-2-yl-1H-imidazo[4,5-f][1,10]phenanthroline) and its ruthenium complexes [Ru(bpy)₂BFIP]²⁺ (bpy = 2,2′-bipyridine), [Ru(dmb)₂BFIP]²⁺ (dmb = 4,4′-dimethyl-2,2′-bipyridine), and [Ru(phen)₂BFIP]²⁺ (phen = 1,10-phenanthroline) have been synthesized and characterized by elemental analysis, mass spectra, IR, UV-Vis, ¹H- and ¹³C-NMR, and cyclic voltammetry. The DNA binding of these complexes to calf-thymus DNA (CT-DNA) was investigated by spectrophotometric, fluorescence, and viscosity measurements. The results suggest that ruthenium(II) complexes bind to CT-DNA through intercalation. Photocleavage of pBR 322 DNA by these complexes was also studied, and [Ru(phen)₂BFIP]²⁺ was found to be a much better photocleavage agent than the other two complexes.     

Synthesis,characterization, antitumor,and cytotoxic activity of mononuclear Ru(II) complexes

In the search for antitumor active metal complexes several ruthenium complexes have been reported to be promising. A series of mononuclear Ru(II) complexes, [Ru(T)₂(S)]²⁺, where T?=?2,2′-bipyridine/1,10-phenanthroline and S?=?CH₃-bitsz, Cl-bitsz, Br-bitsz, tmtsz, dmtsz, have been prepared and characterized by UV-Vis, IR, ¹H-NMR, FAB-mass spectroscopy, and elemental analysis. The complexes were subjected to in vivo anticancer activity against a transplantable murine tumor cell line Ehrlich's ascitic carcinoma (EAC) and in vitro cytotoxic activity against human cancer cell line Molt 4/C₈, CEM, and murine tumor cell line L1210. Ruthenium complexes showed promising biological activity especially in decreasing tumor volume and viable ascitic cell counts. Treatment with these complexes prolonged the life span of EAC-tumor-bearing mice by 10–48%. In vitro evaluation of these ruthenium complexes revealed cytotoxic activity from 0.21 to 24?µmol?L^?1 against Molt 4/C₈, 0.16–19?µmol?L^?1 against CEM, and 0.75–32?µmol?L^?1 against L1210 cell proliferation, depending on the nature of the compound.     

Synthesis,characterization and fluorescence spectra of mixed ligand Zn(II), Cd(II) and Hg(II) complexes with 1,10-phenanthroline-5,6-dione ligand

The novel mixed ligand complexes [M(bpy)(phen-dione)](PF₆)₂ (M?=?Zn(II), Cd(II) and Hg(II), bpy?=?2,2^′-bipyridine and phen-dione?=?1,10-phenanthroline-5,6-dione) have been synthesized and characterized by elemental analysis, IR, ¹H NMR and electronic absorption spectroscopies. The ν(C=O) of coordinated phen-dione in these complexes are very similar to the free phen-dione ligand showing that phen-dione is not coordinated to metal ion from its C=O sites. Absorption spectra of the complexes show two absorption bands for intraligand transitions. These absorption bands show dependence to the dielectric constant of solvent. These complexes exhibit an intensive fluorescence band around 535?nm in DMF when the excitation wavelength is 260?nm at room temperature. The fluorescence intensity of these complexes is larger than that of the free ligand.     

Syntheses,characterization and crystal structures of mixed-ligand Cu(II), Ni(II) and Mn(II) complexes of N-(1-phenyl-3-methyl-4-propenylidene-5-pyrazolone)-salicylidene hydrazide containing ethanol or pyridine as a co-ligand

Five new mixed-ligand complexes [CuL(EtOH)] (1), [NiL(EtOH)₃] (2), [Mn₂L₂(μ₂-EtOH)₂(EtOH)₂] (3), [CuL(Py)] · MeOH (4) and [NiL(Py)₃] (5) (L²⁻ = N-(1-phenyl-3-methyl-4-propenylidene-5-pyrazolone)-salicylidene hydrazide anion, Py = pyridine) have been synthesized and characterized by elemental analyses, IR spectra, thermal analyses and single crystal X-ray diffraction. The crystallographic structural analyses of these complexes reveal that the ligand (H₂L) itself undergoes isomerization from the keto form to the enol form in the reaction, then loses two protons and acts as a double negatively charged tridentate chelating agent coordinated to the metal ion in the solution. The final results show that when a co-ligand was present in the synthetic reaction, other coordination sites around the metal ions Cu²⁺ and Ni²⁺ were completed either by the ethanol or pyridine molecules under the common solvent reaction or solvothermal syntheses conditions, respectively. In the case of the Mn²⁺ ion, it was still coordinated with the solvent molecules regardless of whether it was synthesized under the common solvent reaction or solvothermal syntheses with pyridine. The reason for this difference might be attributed to the fact that the coordination modes and bonding effect of the co-ligand with the metal ions are different, the final complexes tend to form the most stable compound.     

Synthesis,characterization, and antitumor properties of ruthenium(II) anthraquinone complexes

Three new Ru(II) complexes, [Ru(dmb)₂(ipad)](ClO₄)₂ (dmb = 4,4′-dimethyl-2,2′-bipyridine, ipad = 2-(anthracene-9,10-dione-2-yl) imidazo[4,5-f][1,10]phenanthroline, 1), [Ru(dmp)₂(ipad)](ClO₄)₂ (dmp = 2,9-dimethyl-1,10-phenanthroline, 2), and [Ru(dip)₂(ipad)](ClO₄)₂ (dip = 4,7-diphenyl-1,10-phenanthroline, 3), have been synthesized and characterized. The three Ru(II) complexes intercalate with the base pairs of DNA. The in vitro antiproliferative activities and apoptosis-inducing characteristics of these complexes were investigated. The complexes exhibited cytotoxicity against various human cancer cell lines. BEL-7402 cells displayed the highest sensitivity to 1, accounted for by the greatest cellular uptake. Complex 1 was shown to accumulate preferentially in the nuclei of BEL-7402 cells and cause DNA damage and induce apoptosis, which involved cell cycle arrest and reactive oxygen species generation.     

Synthesis, characterization and photophysics of bimetallic manganese(I) and ruthenium(II) complexes

A series of new manganese(I) and ruthenium(II) monometallic and bimetallic complexes made of 2,2′-bipyridine and 1,10-phenanthroline ligands, [Mn(CO)₃(NN)(4,4′-bpy)]⁺, [{(CO)₃(NN)Mn}₂(4,4′-bpy)]²⁺ and [(CO)₃(NN)Mn(4,4′-bpy)Ru(NN)₂Cl]²⁺ (NN = 2,2′-bipyridine, 1,10-phenanthroline; 4,4′-bpy = 4,4′-bipyridine) are synthesized and characterized, in addition to already known ruthenium(II) complexes [Ru(NN)₂Cl(4,4′-bpy)]⁺ and [Cl(NN)₂Ru(4,4′-bpy)Ru(NN)₂Cl]²⁺. The electrochemical properties show that there is a weak interaction between two metal centers in Mn–Ru heterobimetallic complexes. The photophysical behavior of all the complexes is studied. The Mn(I) monometallic and homobimetallic complexes have no detectable emission. In Mn–Ru heterobimetallic complexes, the attachment of Mn(I) with Ru(II) provides interesting photophysical properties.     

Synthesis,structural characterization,oxygen sensitivity,and antimicrobial activity of ruthenium(II) carbonyl complexes with thiosemicarbazones

[Ru(CO)(PPh₃)₂(η³-O,N³,S-TSC¹)] (1), [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC²)] (2), and [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC³)] (3) have been prepared by reacting [Ru(H)(Cl)(CO)(PPh₃)₃] with the respective thiosemicarbazones TSC¹ (2-hydroxy-3-methoxybenzaldehyde thiosemicarbazone), TSC² (3-hydroxybenzaldehyde thiosemicarbazone), and TSC³ (3,4-dihydroxybenzaldehyde thiosemicarbazone) in a 1?:?1 M ratio in toluene and all of the complexes have been characterized by UV–vis, FT-IR, and ¹H and ³¹P NMR spectroscopy. The spectroscopic studies showed that TSC¹ is coordinated to the central metal as a tridendate ligand coordinating via the azomethine nitrogen (C=N), phenolic oxygen, and sulfur to ruthenium in 1, whereas TSC² and TSC³ are coordinated to ruthenium as a bidentate ligand through azomethine nitrogen (C=N) and sulfur in 2 and 3. Oxygen sensitivities of 1–3 and [Ru(Cl)(CO)(PPh₃)₂(η²-N³,S-TSC⁴)] (4), and antimicrobial activities of 1–3 have been determined.     

Synthesis,characterization and catalytic,cytotoxic and antimicrobial activities of two novel cyclotriphosphazene‐based multisite ligands and their Ru(II) complexes

Two novel cyclotriphosphazene ligands ( 2 and 3 ) bearing 3‐oxypyridine groups and their corresponding Ru(II) complexes ( 4 and 5 ) were synthesized and their structures were characterized using Fourier transform infrared, ¹H NMR and ³¹P NMR spectroscopic data and elemental analysis. The Ru(II) complexes were used as catalysts for catalytic transfer hydrogenation of p‐substituted acetophenone derivatives in the presence of KOH. Additionally, the cytotoxic activities of compounds 2 , 3 , 4 , 5 were evaluated against PC3 (human prostate cancer), DLD‐1 (human colorectal cancer), HeLa (human cervical cancer) and PNT1A (normal human prostate) cell lines. Finally the antimicrobial activities of compounds 2 , 3 , 4 , 5 were evaluated against a panel of Gram‐positive and Gram‐negative bacteria and yeast cultures. The complexes showed efficient catalytic activity towards transfer hydrogenation of acetophenone derivatives, especially those bearing electron‐withdrawing substituents on the para‐position of the aryl ring. The compounds were found to have moderate to high cytotoxic and antimicrobial activities, and Ru(II) complexation enhanced both cytotoxic and antimicrobial activities in comparison with the parent compounds. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis and structural characterization of ruthenium complexes with 1-aryl-imidazole-2-thione

Treatment of [RuCl₂(PPh₃)₃] with 2 equiv. Himt^MPh (Himt^MPh?=?1-(4-methyl-phenyl)-imidazole-2-thione) in the presence of MeONa afforded cis-[Ru(κ ²-S,N-imt^MPh)₂(PPh₃)₂] (1), while interaction of [RuCl₂(PPh₃)₃] and 2 equiv. Himt^MPh in tetrahydrofuran (THF) without base gave [RuCl₂(κ ¹-S-Himt^MPh)₂(PPh₃)₂] (2). Treatment of [RuHCl(CO)(PPh₃)₃] with 1 equiv. Himt^MPh in THF gave [RuHCl(κ ¹-S-Himt^MPh)(CO)(PPh₃)₂] (3), whereas reaction of [RuHCl(CO)(PPh₃)₃] with 1 equiv. of the deprotonated [imt^MPh]^? or [imt^NPh]^? (imt^NPh?=?1-(4-nitro-phenyl)-2-mercaptoimidazolyl) gave [RuH(κ ²-S,N-imt^RPh)(CO)(PPh₃)₂] (R?=?M 4a, R?=?N 4b). The ruthenium hydride complexes 4a and 4b easily convert to their corresponding ruthenium chloride complexes [RuCl(κ ²-S,N-imt^MPh)(CO)(PPh₃)₂] (5a) and [RuCl(κ ²-S,N-imt^NPh)(CO)(PPh₃)₂] (5b), respectively, in refluxing CHCl₃ by chloride substitution of the RuH. Photolysis of 5a in CHCl₃ at room temperature afforded an oxidized product [RuCl₂(κ ²-S,N-imt^MPh)(PPh₃)₂] (6). Reaction of 6 with excess [imt^MPh]^? afforded 1. The molecular structures of 1·EtOH, 3·C₆H₁₄, 4b·0.25CH₃COCH₃, and 6·2CH₂Cl₂ have been determined by single-crystal X-ray crystallography.     

Synthesis,characterization and antitumor activity of palladium(II) complexes of monoethyl 8-quinolylmethylphosphonate

The complex-forming properties of monoethyl 8-quinolylmethylphosphonate (8-Hmqmp) towards palladium(II) ion have been investigated by reactions of the hydrochloride, 8-Hmqmp · HCl · H₂O, and sodium salt, Na(8-mqmp) · 2H₂O, of this monoester with palladium(II) halide compounds in aqueous solution over a wide pH range. Depending on pH and initial quinolinium and palladium salts, four types of complexes have been formed. Under acidic solution the ion-pair salt complexes [8-H₂mqmp]₂[PdX₄] (1 and 2, pH < 3) and [8-H₂mqmp]₂[Pd₂X₆] (3 and 4, pH ∼ 3), with protonated quinoline ligand as cation and tetrahalopalladate or hexahalodipalladate complex as anion (X = Cl, Br), were isolated. By heating in methanol the chloro complexes 1 and 3 as well as bromo complexes 2 and 4 were converted into the quinolinium salt complexes, [8-H₂mqmp][Pd(8-Hmqmp)X₃], 5 and 6, respectively, containing as anion the quinoliniummethylphosphonatetrihalopalladate complex with palladium bonded at the phosphonic acid moiety. The chelate complex 7, [Pd(8-mqmp)₂], with ligand bonded through the quinoline nitrogen and the deprotonated phosphonic acid oxygen and forming two seven-membered {N,O} chelate rings, was obtained in neutral and basic media. The complexes were identified and characterized by elemental analysis, magnetic and conductance measurements, spectroscopic studies (IR, ¹H NMR, UV–Vis, positive/negative ion FAB MS) and thermal analysis (TG, DTA). As a preliminary screening for their biological activity, complexes were investigated for their ability to inhibit the cancer growth in vitro in the human KB and murine L1210 cell lines. The results obtained were compared with those obtained for the complexes of diethyl 8-quinolylmethylphosphonate (8-dqmp) and monoethyl 2-quinolylmethylphosphonate (2-Hmqmp), and structural factors that determine the complex activity were discussed.