ClO4 Research Articles

Synthesis of Symmetric Binuclear 5,6-Dihydro-1,2,4,5-tetrazinium Perchlorates

Synthesis of Symmetric Binuclear 5,6-Dihydro-1,2,4,5-tetrazinium Perchlorates

Evidence for the distribution of perchlorates on Mars – ERRATUM

Evidence for the distribution of perchlorates on Mars – ERRATUM

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

AbstractThree 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.

Anion-dependent assembly of four sensitized near-infrared luminescent heteronuclear Zn(II)-Yb(III) Schiff base complexes from a trinuclear Zn(II) complex.

Four anion-dependent 0D Zn(II)-Yb(III) heterometallic Schiff base complexes, [YbZn2L2(OAc)4]·ClO4 (2), YbZnL2(NO3)3 (3), [(YbL)2(H2O)Cl(OAc)]2·[ZnCl4]2 (4), and YbZnL(OAc)4 (5), were assembled through central metal substitution or reconstruction from homotrinuclear Zn(II) complex {[(Zn(OAc)(H2O)L]2Zn}(ClO4)2·4H2O [1; HL = 2-ethoxy-6-[(pyridin-2-ylmethylimino)methyl]phenol] with different Yb(III)X3 salts [X = ClO4 (2), NO3 (3), Cl (4), and OAc (5)], in which the Zn(II)-sensitized near-infrared luminescent performances in the four complexes 2-5 are closely related to their structural models.

ChemInform Abstract: Reactions of 4‐Oxobenz[1,3‐b]oxazinium Perchlorates with α‐Aminoazoles.

AbstractThe reaction of oxazinium perchlorates (I) or (IV) with different aminoazoles is studied.

Lithium and Magnesium Separation from Salt Lake Brine by Tributyl Phosphate under Action of Co-extraction Reagent ClO4-

Lithium and Magnesium Separation from Salt Lake Brine by Tributyl Phosphate under Action of Co-extraction Reagent ClO4-

Interaction of 1,4,8,9-Tetraazatriphenylene-Copper (II)-L-Serinate (L-Argininate) Complexes with DNA

采用电子吸收光谱、荧光光谱、粘度测定和琼脂糖凝胶电泳方法研究了配合物[Cu（TATP）（L-Ser）（H2O）]·ClO4（1）和[Cu（TATP）（L-Arg）（H2O）]2ClO4·0.5H2O（2）（TATP=1,4,8,9-四氮三联苯,L-Ser=L-丝氨酸,L-Arg=L-精氨酸）与DNA之间的相互作用.结果表明,配合物电子吸收光谱的最大吸收峰在加入DNA后产生明显的减色效应,配合物能极大地淬灭溴化乙啶（EB）-DNA体系的荧光,DNA的粘度随配合物浓度的增加而增大,表明配合物对DNA有较强的插入作用,作用力大小为配合物2〉1;另外,凝胶电泳实验结果表明配合物在维生素C存在的条件下对pBR322DNA具有显著的断裂作用.

Non-equivalent water molecules in [Ni(H2O)6](ClO4)2 and in [Ni(D2O)6](ClO4)2 in the thermogravimetric investigations

The thermal decomposition of [Ni(H2O)6](ClO4)2 and [Ni(D2O)6](ClO4)2 were studied by thermogravimetric analysis (TG) and simultaneous differential thermal analysis (SDTA) at a constant heating rate. The gaseous products of the decomposition were on-line identified by a quadrupole mass spectrometer (QMS). In both cases the process of decomposition starts at ca. 410 K and is connected with removal of water molecules in a stepwise way; at the beginning the first water molecule is lost, then the second and at higher temperature the third one. The rest of the water molecules are lost in the temperature region of Cl O4 – decomposition. The energy of activation of the process was calculated in both cases.

Determination of low levels of perchlorate in lettuce and spinach using ion chromatography-electrospray ionization mass spectrometry (IC-ESI-MS).

A sample preparation method was developed to quantify environmentally relevant (low micrograms per liter) concentrations of perchlorate (ClO4(-)) in leafy vegetables using IC-ESI-MS. Lettuce and spinach were macerated, centrifuged, and filtered, and the aqueous extracts were rendered water-clear using a one-step solid-phase extraction method. Total time for extraction and sample preparation was 6 h. Ion suppression was demonstrated and was likely due to unknown organics still present in the extract solution after cleanup. However, this interference was readily eliminated using a Cl(18)O4(-) internal standard at 1 microg/L in all standards and samples. Hydroponically grown perchlorate-free butterhead lettuce was spiked to either 10.3 or 37.7 microg/kg of fresh weight (FW), and recoveries were between 91 and 98% and between 93 and 101%, respectively. Five types of lettuce and spinach from a local grocery store were then analyzed; they contained from 0.6 to 6.4 microg/kg of FW. Spike recoveries using the store-bought samples ranged from 89 to 100%. The method detection limit for perchlorate in plant extracts is 40 ng/L, and the corresponding minimum reporting limit is 200 ng/L or 0.8 microg/kg of FW.

2,4,6-Tris(2-pyridyl)-1,3,5-triazine (tptz)-Derived [RuII(tptz)(acac)(CH3CN)]+and Mixed-Valent [(acac)2RuIII{(μ-tptz-H+)-}RuII(acac)(CH3CN)]+

Mononuclear [Ru(II)(tptz)(acac)(CH3CN)]ClO4 ([1]ClO4) and mixed-valent dinuclear [(acac)2Ru(III){(mu-tptz-Eta+)-}Ru(II)(acac)(CH3CN)]ClO4 ([5]ClO4; acac = acetylacetonate) complexes have been synthesized via the reactions of Ru(II)(acac)2(CH3CN)2 and 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz), in 1:1 and 2:1 molar ratios, respectively. In [1]ClO4, tptz binds with the Ru(II) ion in a tridentate N,N,N mode (motif A), whereas in [5]ClO4, tptz bridges the metal ions unsymmetrically via the tridentate neutral N,N,N mode with the Ru(II) center and cyclometalated N,C- state with the Ru(III) site (motif F). The activation of the coordinated nitrile function in [1]ClO4 and [5]ClO4 in the presence of ethanol and alkylamine leads to the formation of iminoester ([2]ClO4 and [7]ClO4) and amidine ([4]ClO4) derivatives, respectively. Crystal structure analysis of [2]ClO4 reveals the formation of a beautiful eight-membered water cluster having a chair conformation. The cluster is H-bonded to the pendant pyridyl ring N of tptz and also with the O atom of the perchlorate ion, which, in turn, makes short (C-H- - - - -O) contacts with the neighboring molecule, leading to a H-bonding network. The redox potentials corresponding to the Ru(II) state in both the mononuclear {[(acac)(tptz)Ru(II)-NC-CH3]ClO4 ([1]ClO4) >> [(acac)(tptz)Ru(II)-NH=C(CH3)-OC2H5]ClO4 ([2]ClO4) > [(acac)(tptz)Ru(II)-NH2-C6H4(CH3)]ClO4 ([3]ClO4) > [(acac)(tptz)Ru(II)-NH=C(CH3)-NHC2H5]ClO4 ([4]ClO4)} and dinuclear {[(acac)2Ru(III){(mu-tptz-H+)-}Ru(II)(acac)(NC-CH3)]ClO4 ([5]ClO4), [(acac)2Ru(III){(mu-tptz-H+(N+-O-)2)-}Ru(II)(acac)(NC-CH3)]ClO4 ([6]ClO4), [(acac)2Ru(III){(mu-tptz-H+)-}Ru(II)(acac)(NH=C(CH3)-OC2H5)]ClO4 ([7]ClO4), and [(acac)2Ru(III){(mu-tptz-Eta+)-}Ru(II)(acac)(NC4H4N)]ClO4 ([8]ClO(4))} complexes vary systematically depending on the electronic nature of the coordinated sixth ligands. However, potentials involving the Ru(III) center in the dinuclear complexes remain more or less invariant. The mixed-valent Ru(II)Ru(III) species ([5]ClO4-[8]ClO4) exhibits high comproportionation constant (Kc) values of 1.1 x 10(12)-2 x 10(9), with substantial contribution from the donor center asymmetry at the two metal sites. Complexes display Ru(II)- and Ru(III)-based metal-to-ligand and ligand-to-metal charge-transfer transitions, respectively, in the visible region and ligand-based transitions in the UV region. In spite of reasonably high K(c) values for [5]ClO4-[8]ClO4, the expected intervalence charge-transfer transitions did not resolve in the typical near-IR region up to 2000 nm. The paramagnetic Ru(II)Ru(III) species ([5]ClO4-[8]ClO4) displays rhombic electron paramagnetic resonance (EPR) spectra at 77 K (g approximately 2.15 and Deltag approximately 0.5), typical of a low-spin Ru(III) ion in a distorted octahedral environment. The one-electron-reduced tptz complexes [Ru(II)(tptz.-)(acac)(CEta3CN)] (1) and [(acac)2Ru(III){(mu-tptz-Eta+).2-}Ru(II)(acac)(CH3CN)] (5), however, show a free-radical-type EPR signal near g = 2.0 with partial metal contribution.

Chloride Interactions with Iron Surfaces: Implications for Perchlorate and Nitrate Remediation Using Permeable Reactive Barriers

Perchlorate (Cl O4− ) can be reduced by iron surfaces, suggesting that permeable reactive barriers may represent a useful groundwater remediation strategy. However, chloride produced by the reaction inhibits further perchlorate removal. Adsorption of chloride on iron filings was investigated as a potential mechanism of chloride interference. The effect of chloride on the removal of nitrate, another oxyanion reactive at iron surfaces, was also investigated to draw more general conclusions about anion competition when target compounds adsorb electrostatically. A triple layer adsorption model was used to describe chloride sorption isotherms on the iron filings using magnetite as the model surface and defining a single type of surface hydroxyl sorption site. The model considered electrostatic attraction, specific sorption, and the effect of adsorbed Fe2+ on chloride sorption. Experimental and modeling results indicate that chloride competition is probably not of concern for nitrate reduction in permeable reac...

A Novel Synthesis of Tri‐ and Tetra‐phenylpyrylium Perchlorates from Phenyl‐Substituted Cyclopentadienes.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Three Modifications of [Pr2(ClO4)2 (H2I2O10)]×8H2O — A Theme with Variations.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Substitutions of organopalladium(II) species with benzimidazole derivatives

The [Pd(cod)(cotl)]ClO4 complex (cod ¼ cycloocta-1,5-diene; cotl ¼ cyclooctenyl, C18H �) undergoes substitutions with new Schiff base ligands containing benzimidazole L [L ¼ 2-(2¢-N-n-propylidenephenyl)benzimidazole (L 1 ); 2(2¢-N-i-propylidenephenyl)benzimidazole (L 2 ); 2-(2¢-N-n-butylidenephenyl)benzimidazole (L 3 ); 2-(2¢-N-i-butylidenephenyl)benzimidazole (L 4 )]. Facile displacement of cod by L occurs to produce complexes of the type [Pd(cotl)L]ClO4 AE nMe2CO (n ¼ 0; L ¼ L 1 ,L 2 or L 3 ; n ¼ 2, L ¼ L 4 ). Dihalobridge complexes of the type [Pd(cotl)X]2 (X ¼ Cl or Br) undergo halogen-bridge cleavage with L 1 –L 4 to give mononuclear complexes of the type Pd(cotl)LX AE nH2 O( n ¼ 2, X ¼ Cl, L ¼ L 1 ; n ¼ 0, X ¼ Br, L ¼ L 1 ; n ¼ 0, X ¼ Cl, L ¼ L 2 ; n ¼ 0, X ¼ Cl or Br, L ¼ L 3 ; n ¼ 0, X ¼ Cl, L ¼ L 4 ; n ¼ 2, X ¼ Br, L ¼ L 4 ) and a binuclear complex [Pd(cotl)Br]2L 2 . The complexes were characterised by physical properties, i.r., 1 H- and 13 C-n.m.r. spectral techniques and by mass spectra. Probable

Lanthanide Complexes with 1,1′‐Diactylferrocene bis‐2‐Furoylhydrazone

A ligand, 1,1′‐diacetylferrocene bis‐2‐furoylhydrazone (H2Bafh), and its lanthanide [Ln(III)] complexes, [Ln(H2Bafh)3] · (ClO4)3 · nH2O [complexes A: Ln = La(III), Gd(III), Tm(III), Yb(III)], and [Ln(H2Bafh)Cl2] · Cl · nH2O [complexes B: Ln = Y(III), La(III), Nd(III), Gd(III), Tm(III)] were prepared and characterized by microanalyses, IR, 1H NMR, and UV‐VIS spectra, molar conductivity, and TGA analyses.

Polyazolyl Chelate Chemistry. 12.1 An Unusual Mode of Coordination for the Hydrotris(methimazolyl)borato Ligand

The reactions of [RuHCl(CO)(PPh3)3] or [RuH(NCMe)2(CO)(PPh3)2]ClO4 with Na[HB(mt)3] (mt = methimazolyl) provide the structurally characterized complex [RuH(CO)(PPh3){κ3-H,S,S‘ ‘-HB(mt)3}], which hydrogenates ethynylbenzene to styrene with formation of the ruthenaboratrane [Ru(CO)(PPh3){B(mt)3}](Ru→B).

Synthesis and crystal structure of nickel(II) and zinc(II) complexes with 2,4-bis(3,5-dimethylpyrazol-1-yl)-6-methoxyl-1,3,5-triazine

2,4-Bis(3,5-dimethylpyrazol-1-yl)-6-methoxyl-1,3,5-triazine(bpt) has been synthesized by using a new, simple and general method with high yields. Reactions of bpt with Ni(ClO 4 ) 2 6H 2 O and Zn(ClO 4 ) 2 6H 2 O in methanol gave mononuclear complex [Ni(bpt) 2 ] (ClO 4 ) 2 H 2 O and ternary complex [Zn(mpt) 2 (dmp)](ClO 4 ) 2 respectively, where mpt (2,4-dimethoxy-6-(3,5-dimethylpyrazol- 1-yl)-1,3,5-triazine) and dmp(3,5-dimethylpyrazole) are the alcoholysis products of bpt in the presence of Zn 2+ ion. A possible mechanism for this catalytic reaction was proposed. X-ray crystal structure for ligand bpt, Ni and Zn complexes are reported. The protonated form of the ligand bpt crystallizes as its perchlorate salt including one molecule of water, [Hbpt H 2 O ClO 4 ]. The proton is located on one pyrazole N-atom. [Hbpt H 2 O ClO 4 ], in which [Hbpt] + is in cis-cis conformation, are packed in slipped stacks of approximately parallel layers. The π-π overlap interactions between the non-protonized pyrazoles of the adjacent layers give a zigzag arrangement of the planar aromatic [Hbpt] + molecules. In [Ni(bpt) 2 ](ClO 4 ) 2 H 2 O, bpt are meridionally three-coordinated with Ni 2+ . The coordination sphere around Ni 2+ is a slightly distorted square bipyramid, where four pyrazole nitrogen atoms occupy the basal positions and two triazine nitrogen atoms the apical one. In [Zn(mpt) 2 (dmp)](ClO 4 ) 2 , the Zn atom is coordinated with a pair of bidentate mpt ligands and one monodentate dmp ligand, forming a distorted trigonal bipyramid, where the two triazine nitrogen atoms of mpt and one nitrogen atom of dmp occupy the basal positions, and the two pyrazole nitrogen atoms of mpt the apical one.

A NEW APPROACH TO PREPARATION OF 1,3-DITHIOLIUM SALTS

The synthesis of 4-(3′,5′-diiodo-2′-hydroxy-phenyl)- 2-(N,N-dialkylamino)-1,3-dithiolium perchlorates has been performed by cyclization of the corresponding N,N-dialkylaminocarbodithioates in presence of the “superacid” mixture P2O5–CH3SO3H.

Synthesis, crystal structure of diferrous complex and its reactivity with dioxygen

The dinuclear complex of [Fe2L{O2P(OPh)2}](ClO4)2· Et2O(1) (where L represents the dinucleating ligand N-Et-HPTB, anion of N, N, N’, N’-tetrakis (N-ethyl-2-benzimidazolyemethyl)2-hydroxy-1, 3-diamino-propane) has been synthesized and crystallizes in the triclinic space group P1 with cell constants a = 1.526(3) nm, b = 1.259 8(3) nm, c = 1.563 0(3)° nm, α = 94.41(3)°, β = 115.31(3)°, γ = 99.90(3)°, V = 3.267(1) nm3, z = 2, R = 0.084 7 and Rw = 0.177 8. The Fe(II) sites are bridged by an alkoxide of the dinucleating ligand and a phosphate, affording a diiron core with an Fe-μ-O-Fe angle of 131.20(3)° and an Fe-Fe distance of 0.364 9 nm. Both Fe(II) centers have trigonal bipyramidal geometry. Dioxygen adduct (1/O2) forms upon exposure of the diferrous complex to O2 at low temperature (?60°C). The 1/O2 adduct is stable at ? 60°C but decomposes upon warming. The adduct exhibits visible absorption maximum near 606 nm and resonance Raman features at 478 cm-1 (γFe-O) and 897 cm-1 (γO-O), and the latter is the characteristic of a μ-1,2-peroxo species, indicating that dioxygen adducts can serve as models for the putative oxygenated intermediate of some non-heme diiron-oxo proteins.

Oscillating Reactions of NaBrO3-MA-H3PO4 System Catalyzed by Tetraazamacrocyclic Nickel(II) Complex

New oscillating reactions catalyzed by a tetraazamacrocyclic nickel(Ⅱ) complex NiL(ClO4)2, where L is 2,4,4,9,11,11-hexamethyl-1,5,8,12-tetraazabutadecacyclo-1,5,8,12-tetraene, in acidic bromate medium have been studied. The concentration ranges of main reactant within which the oscillations were observed in the system were obtained. The influences of temperature, Vc ,Br-, Ag+, Hg2+, acetonitrile or acrylamide on the oscillations were discussed. The results indicated that Br-played an important role in the control reaction progress and free radicals, Br2might be involved in the reaction process. It was found that the stirring rate can affect oscillating reactions. The oscillation trajectories of this system were recorded. They were different from classical BZ reaction and some other tetraazamacro-cyclic complexes catalyzed systems.