Characterization of Diastereoisomeric [Ni(Me8[14]ane)]2+ Cations

The isomeric Me₈[l4]anes, designated by L_A, L_B and L_C, on reaction with nickel(II) acetate tetrahydrate and subsequent addition of LiClO₄·3HO yield yellow or orange-yellow square planar [NiL](ClO₄)₂ diastereoisomers. It has been possible to isolate two N-chiral diastereoisomers for each ligand and these give distinct infrared and ¹H NMR spectra. The structures of these isomers have been assigned mainly on the basis of their ¹H NMR spectra. One structure, namely [NiL_Bα ](ClO₄)₂, has been confirmed by x-ray crystallography.     

Preparation,Spectroscopic Properties and Characterization of Oxovanadium(IV), Isothiocyanatomanganese(III), Cyanocobalt(III) and Cobalt(II) Complexes with a Bis-Crown Ether Tetraaza[14]Annulene

Oxovanadium(IV), isothiocyanatomanganese(III), cyanocobalt(III) and cobalt(II) complexes of tetraaza[14]annulene appended with two crown ethers at 2,3- and 11,12-positions have been prepared. Cation complexation behavior of these cavity-bearing tetraaza[14]annulene complexes has been investigated by optical absorption methods. The cation K + , which necessitates two crown ether cavities for complexation, induces dimerization of the tetraaza[14]annulene complexes, whereas the Na + does not. Formation of the sandwich complexes due to dimerization is hindered by the steric interactions involving the axial ligand as judged by the blue shift of the intense band around 385-425 nm. Judging from its ESR spectrum, the cobalt(II) complex becomes a monomeric dioxygen complex of a 1 : 1 molar ratio in the presence of O 2 and pyridine at 77 K.     

Synthesis,characterization, and DNA-binding of [Co(phen)2(CPIA)]3+, [Co(phen)2(BIP)]3+, and [Co(phen)2(CIP)]3+

Three ligands, 2-(3-(carboxymethyl)-1,10-phenanthroline-[5,6-d]imidazole-1-yl)acetate (CPIA), 2-(benzo[d][1,3]dioxol-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (BIP), and 2-(9H-carbazol-3-yl)-1H-imidazo[4,5-f][1,10]phenanthroline (CIP), and their complexes, [Co(phen)₂(CPIA)]³⁺ (1) (phen = 1,10-phenanthroline), [Co(phen)₂(BIP)]³⁺ (2), and [Co(phen)₂(CIP)]³⁺ (3), have been synthesized and characterized. Binding of the three complexes with calf thymus DNA (CT-DNA) has been investigated by spectroscopic methods, cyclic voltammetry, and viscosity measurements. The three complexes bind to DNA through an intercalative mode, and the size and shape of the intercalative ligands have significant effects on the binding affinity of complexes to CT-DNA.     

Rhodium(III)-Catalyzed C-H/O2 Dual Activation and Macrocyclization: Synthesis and Evaluation of Pyrido[2,1-a]isoindole Grafted Macrocyclic Inhibitors for Influenza H1N1

The development of environment-friendly, step economic couplings to generate structurally diverse macrocyclic compounds is highly desirable but poses a marked challenge. Inspired by the C−H oxidation mechanism of cytochromes P450, an unprecedented and practical Rh^III-catalyzed acylmethylation macrocyclization via C−H/O₂ dual activation has been developed by us. The process of macrocyclization is facilitated by a synergic coordination from pyridine and ester group. Interestingly, the reaction mode derives from a three-component coupling which differs from established olefination and alkylation paths. Density functional theory (DFT) calculations and control experiments revealed the mechanism of this unique C−H/O₂ dual activation. The newly achieved acylmethylation macrocyclic products and their derivatives showed a potent anti-H1N1 bioactivity, which may provide an opportunity for the discovery of novel anti-H1N1 macrocyclic leading compounds.     

Catalytic [2+2+1] Synthesis of Fused Thiophenes Using Thiocarbonyls as Sulfur Donors

The use of N‐(p‐chlorophenyl)methylbenzoxazole‐2‐thione as a sulfur‐atom donor enables the catalytic [2+2+1] cycloaddition of diynes in wet DMF at 80 °C when open to air, thus affording diverse fused thiophenes with good yields and wide functional‐group compatibility. A plausible mechanism, involving a cationic ruthenacycle intermediate, was also proposed on the basis of several control experiments.     

CHARACTERIZATION OF GALLIUM-NITROGEN ADDUCTS BY X-RAY STRUCTURAL AND NMR SPECTRAL STUDIES. CRYSTAL STRUCTURE OF [(PhMe2CCH2)2GaCI]2 AND OF ITS MONOMERIC t-BUTYLAMINE ADDUCT, (PhMe2CCH2)2GaCI[NH2(t-Bu)]

Abstract

The nature of [(PhMe₂CCH₂)₂GaCl]₂ and its adducts with NH₂(t-Bu) and NH₂(n-Pr) have been investigated. [(PhMe₂CCH₂)₂GaCl]₂ crystallizes in the monoclinic space group P2₁/c with a=11.2495(16)Å, b = 21.4977(32)A, c = 7.8337(15)Å, β = 93.489(14)°, V= 1891.0(5)ų and D(calcd.)= 1.305 Mg/m³ for Z = 2. The structure was refined to R(F) = 4.2% for 1672 reflections above 6[sgrave](F). The molecule has perfect C_i symmetry, a planar Ga(μ-Cl)₂Ga core and an expanded C(α)-Ga-C(α) angle of 137.9(3)° between the neophyl ligands. (PhMe₂CCH₂)₂-GaCl[NH₂(t-Bu)] crystallizes in the monoclinic space group P2₁/n with a = 6.4023(10) A, b= 17.4274(25) A, c = 22.2389(38) Å, β = 94.939(13)°, V= 2472.2(7)ų and D(calcd.) = 1.225 Mg/m³ for Z = 4. This structure was refined to R(F) = 3.9% for 1700 reflections above 6[sgrave](F). The crystal structure is stabilized by intermolecular Cl … H-N hydrogen bonds and the central Ga(III) atom has a distorted tetrahedral geometry. A benzene solution of (PhMe₂-CCH₂)₂GaCl[NH₂(t-Bu)] is in equilibrium with [(PhMe₂CCH₂)₂GaCl]₂[NH₂(t-Bu)] and free amine according to ¹HNMR studies. In contrast to this, a solution of (PhMe₂CCH₂)-GaCl₂[NH₂(t-Bu)] is in equilibrium with [(PhMe₂CCH₂)GaCl₂]₂[NH₂(t-Bu)], free [(PhMe₂-CCH₂)-GaCl₂]₂ and free amine. Solutions of (PhMe₂CCH₂)₂GaCI[NH₂(n-Pr)] and (PhMe₂CCH₂)GaCl₂[NH₂(n-Pr)] show no evidence for similar equilibria.     

硫化CoMo/Al2O3-TiO2催化剂上CO催化还原SO2的研究

报导了Al2O3、Al2O3-TiO2和TiO2担载的硫化CoMo催化剂上CO催化还原SO2的规律性,结果表明，反应物分别在350 ℃、350～400 ℃间和400 ℃完全转化为CO2和元素S.在含TiO2的催化剂上,CO-SO2反应可同时按COS中间物机理和Redox机理进行,从而使尾气中COS的含量大为降低,提高了生成元素S的选择性.对反应机理进行了讨论.     

Syntheses and Structures of two Cobalt Coordination Polymers with Iminodiacetate Ligands: [CoII2(ida)2(H2O)2]n and [Na2CoIII2(ida)4(H2O)4]n·2nH2O

Two cobalt coordination polymers [Co^II₂(ida)₂(H₂O)₂]_n ( 1 ) and [Na₂Co^III₂(ida)₄(H₂O)₄]_n·2nH₂O ( 2 ) (H₂ida = iminodiacetic acid) have been synthesized and characterized by single‐crystal X‐ray diffraction analysis. Compound 1 exhibits a two‐dimensional framework, in which two cobalt atoms exhibit different coordination environments: one is equatorially coordinated by two ida ligands, while another is coordinated by two water molecules and four ida ligands. It is most interesting that, in compound 2 , the ida ligands exhibit different coordination modes. The organic coordination anions [Co^III(ida)₂]^— are linked up by sodium ions to form a two‐dimensional layer.     

Solvolysis Products of the Types [RhMeL2(Me3[9]aneN3)]2+ and [RuCl3—XLX(Me3[9]aneN3)](x)+ (x = 1‐2) and Preparation and Structure of [Ru([9]aneS3)(Me3[9]aneN3)](CF3SO3)2

Solvolysis of [RhMe(CF₃SO₃)₂(Me₃[9]aneN₃)] ( 1 ) (Me₃[9]aneN₃ = 1, 4, 7‐trimethyl‐1, 4, 7‐triazacyclononane) in CH₃CN, DMSO or pyrazole (L) leads to substitution of both trifluoromethylsulfonate ligands and formation of the cationic complexes [RhMeL₂(Me₃[9]aneN₃)](CF₃SO₃)₂ 3—5 . In contrast, treatment of [RuCl₃(Me₃[9]aneN₃)] ( 2 ) with Ag(CF₃SO₃) in a 1:3 ratio for 2h in CH₃CN leads to formation of the tetranuclear complex [{RuCl₃(Me₃[9]aneN₃)}₂Ag₂(CF₃SO₃)(CH₃CN)](CF₃SO₃) · CH₃CN ( 6 ) with a novel [(RuCl₃)₂Ag₂] core. More forcing conditions enable the substitution of respectively one or two chloride ligands by CH₃CN (reflux 18h) or DMF (85°C, 1h) to afford [RuCl₂(CH₃CN)(Me₃[9]aneN₃)](CF₃SO₃) ( 7 ) and [RuCl(DMF)₂(Me₃[9]aneN₃)](CF₃SO₃)₂ ( 8 ). The heteroleptic sandwich complex [Ru([9]aneS₃)(Me₃[9]aneN₃)](CF₃SO₃)₂ ( 9 ) can be prepared by reduction of 2 with Zn powder in acetone in the presence of 3 equiv. of Ag(CF₃SO₃), followed by addition of [9]aneS₃ (1, 4, 7‐trithiacyclononane). The redox potential E°(Ru³⁺/Ru²⁺) of +1.87 V vs NHE for 9 is only —0.12 V lower than that of the homoleptic complex [Ru([9]aneS₃)₂]²⁺. Crystal structures are reported for 3 — 9 .     

Sodium Hydroxide (NaOH)-Mediated Oxidative Hydroxylation of Arylboronic Acids and Its Applications in C-O Bond Formation

We have developed a straightforward methodology for converting arylboronic acids into phenols using NaOH-mediated air oxidation. This reaction offers several advantages, including simple operation, excellent tolerance towards various functional groups, and scalability. The transmetalation of the resulting borate ester with NaOH occurs readily, enabling convenient derivatization of the borate ester into aryl ethers and esters using alkyl and acyl halides.     

Syntheses and Structures of two 1‐D Complexes, [Co(dmf)2(NCNCN)2] and [Cu(bipy)(NCNCN)]ClO4 with Bridging Dicyanamide Ligands

Two novel dicyanamide complexes [Co(dmf)₂(NCNCN)₂] ( 1 ) and [Cu(bipy)(NCNCN)]ClO₄ ( 2 ) have been synthesized and structurally characterized. 1 crystallizes in the monoclinic space group C2 with a = 13.568(6)Å, b = 7.403(3)Å, c = 8.118(3)Å and Z = 2, whereas 2 crystallizes in the monoclinic system, Cc group, a = 14.270(7)Å, b = 9.143(5)Å, c = 12.371(1) Å, β = 118.612(7)°, and Z = 4. According to X‐ray crystallographic studies, in complex 1 each Co^II ion is six‐coordinated with four nitrogen atoms from four μ_{1, 5}‐dca (dca = dicyanamide) ligands and two oxygen atoms from two dmf ligands to form distorted octahedra. 1 forms a 1‐D network bridged via μ_{1, 5}‐dca. 2 consists of a uniform Cu(NCNCN)Cu chain, each Cu^II ion is octahedrally coordinated with four nitrogen atoms from two μ_{1, 5}‐dca ligands and one bipy ligand and two oxygen atoms from two ClO₄^— ions. The octahedral Cu^II ion shows a significant Jahn‐Teller distortion, with two axial oxygen atoms considerably farther from the copper than the four equatorial nitrogens.     

Regioselective Substitution Reactions of Sulfur(VI)-Nitrogen-Phosphorus Rings: Reactions of the Halogenated Cyclic Thionylphosphazenes [NSOX(NPCl(2))(2)] (X = Cl or F) with Oxygen-Based Nucleophiles

The reactions of the cyclic thionylphosphazenes [NSOX(NPCl(2))(2)] (1, X = Cl; 2, X = F) with three oxygen-based nucleophiles of increasing basicity, sodium phenoxide (NaOPh), sodium trifluoroethoxide (NaOCH(2)CF(3)), and sodium butoxide (NaOBu) have been studied. The reaction of 1 and 2 with 4 equiv of NaOPh at 25 degrees C yielded the regioselectively tetrasubstituted species [NSOX{NP(OPh)(2)}(2)] (5d, X = Cl; 6d, X = F). Further reaction of 5d with an additional 2 equiv of NaOPh over several days or at elevated temperatures gave the fully substituted compound [NSO(OPh){NP(OPh)(2)}(2)] (5e), whereas 6d did not react further. The reaction of 1 and 2 with 5 equiv of NaOCH(2)CF(3) yielded in both cases [NSO(OCH(2)CF(3)){NP(OCH(2)CF(3))(2)}(2)] (7e), and similarly reaction with 5 equiv of NaOBu yielded [NSO(OBu){NP(OBu)(2)}(2)] (9e). In all cases, the reactions were monitored by (31)P NMR and (where applicable) (19)F NMR and were found to involve complete substitution at phosphorus via a predominantly vicinal pathway, followed by substitution at sulfur. Substitutional control of the reactions of NaOPh, NaOBu, with 1 and 2 was found to conform to the following general order of reactivity, PCl(2) > PCl(OR) > SOX (X = Cl, F). Although the reaction with NaOCH(2)CF(3) followed the same order of reactivity, a significant enhancement of reaction rate was detected with each equivalent of trifluoroethoxide added. Reaction of 7e with excess NaOCH(2)CF(3) led to elimination of (CF(3)CH(2))(2)O and the formation of the salts Na[NSO(OCH(2)CF(3))NP(OCH(2)CF(3))(2)NP(OCH(2)CF(3))O] (11) and Na[NS(O)O{NP(OCH(2)CF(3))(2)}(2)] (12). Crystals of 6d are triclinic, space group P&onemacr;, with a = 9.789(3) ?, b = 11.393(4) ?, c = 12.079(5) ?, alpha = 107.40(3) degrees, beta = 91.23(3) degrees, gamma = 93.18(3), V = 1283.6(8) ?(3), and Z = 2. Crystals of 5e are monoclinic, space group C2/c, with a = 32.457(3) ?, b = 10.747(1) ?, c = 18.294(2) ?, beta = 110.37(1) degrees, V = 5982.4(9) ?(3), and Z = 8.     

The coordination chemistry of thiazoline/thiazolidine derivatives. II: synthesis and characterization of [CoCl2(PyTT)] and [ZnCl2(PyTT)] [PyTT=2-(2-pyridyl)imino-N-(2-thiazolin-2-yl)thiazolidine]

The compounds dichloro[2-(2-pyridyl)imino-κN---N-(2-thiazolin-κN-2-yl)thiazolidine]cobalt(II) and dichloro[2-(2-pyridyl)imino-κN---N-(2-thiazolin-κN-2-yl)thiazolidine]zinc(II) have been isolated and characterized by single crystal X-ray diffraction and IR spectroscopy. Moreover, the cobalt(II) complex has been studied by means of magnetic susceptibility measurements and UV–Vis–NIR diffuse reflectance. Both complexes are isostructural. The environment around the cobalt(II) and zinc(II) atoms may be described as a distorted tetrahedral geometry with the metallic atoms coordinated to two chlorine atoms [Co---Cl(1)=2.241(1) Å; Co---Cl(2)=2.221(1) Å], [Zn---Cl(1)=2.235(1) Å; Zn---Cl(2)=2.211(1) Å], one thiazoline nitrogen [Co---N(1)=1.982(2) Å], [Zn---N(1)=2.021(2) Å] and one imino nitrogen [Co---N(3)=2.009(1) Å], [Zn---N(3)=2.056(2) Å].     

Hydrogen‐Atom Transfer in Reactions of Organic Radicals with [CoII(por)]. (por=Porphyrinato) and in Subsequent Addition of [Co(H)(por)] to Olefins

Do the hydrogen shuffle! DFT calculations and experiments reveal low‐barrier multistep pathways for hydrogen‐atom transfer from organic radicals to [Co^II(por)] ^. to form [Co(H)(por)], and for the radical pathway leading to net olefin insertion into the Co? H bond of [Co(H)(por)] (see scheme). The results suggest that hydrogen‐atom‐transfer pathways could be important in numerous addition reactions of M? H complexes with unsaturated substrates.

     

Crystal Structures and Hydrogen Bonding of Two Complexes containing the [Ammine‐chlorido‐ethylenediamine‐bis(pyridine)cobalt(III)]2+ Cation

The crystal structures of two classical cobalt(III) complexes comprising the [CoCl(NH₃)(en)(py)₂]²⁺ cation were determined by single‐crystal X‐ray diffraction. Both complexes, dark red [CoCl(NH₃)(en)(py)₂]Cl₂ · H₂O ( 1 ) and purple [CoCl(NH₃)‐(en)(py)₂][HgCl₄] · 1.125H₂O ( 2 ), crystallize in the triclinic space group P1 . In both compounds, the Co atom exhibits a typical octahedral coordination and the configuration index of the complex is OC‐6‐43. In the case of the chloride ( 1 ), the asymmetric unit comprises one formula unit, whereas there are two formula units in the case of the tetrachloridomercurate ( 2 ). Complex cations, anions, and crystal water molecules are interconnected by various N–H ··· N, N–H ··· Cl, N–H ··· O, O–H ··· Cl, and O–H ··· O bridge bonds. As a result, compound 1 features a two‐dimensional layer structure and compound 2 exists as a three‐dimensional network.     

Effect of substituents on DNA-binding behaviors of ruthenium(II) complexes: [Ru(dmb)2(dtmi)]2+ and [Ru(dmb)2(dtni)]2+

Two Ru(II) complexes [Ru(dmb)₂(dtmi)](ClO₄)₂ (1) (dmb = 4, 4′-dimethyl-2, 2′-bipyridine, dtmi = 3-(pyrazin-2-yl)-as-triazino[5, 6-f]-5-methoxylisatin) and [Ru(dmb)₂(dtni)](ClO₄)₂ (2) (dtni = 3-(pyrazin-2-yl)-as-triazino[5, 6-f]-5-nitroisatin) have been synthesized and characterized by elemental analysis, ES-MS, and ¹H NMR. DNA-binding behaviors of these complexes have been investigated by spectroscopic titration, viscosity measurements, and thermal denaturation. The results indicate that the two complexes interact with calf thymus DNA by intercalation.     

Reactions of 3-[N-chloroacetylamino-N-(4-nitrophenyl)]-2-formylindole with alkylamines

The reactions of 3-[N-chloracetylamino-N-(4-nitrophenyl)]-2-formylindole (1a) with 2-(N, N-dialkylamino)ethylamines afford complex condensation products 7b,c consisting of two similar but not identical diazepinoindole fragments. For the reaction of compound 1a with 3-(N,N-diethylamino)propylamine, the process occurs in a different manner, and the predominant product is 4-ethylaminopropyl-1-(4-nitrophenyl)-2-oxo-1,2,3,4,5,6-hexahydro[1,4]diazepino[6,5-b]indole hydrocloride (14). Two routes of these unexpected transformations were proposed. The structures of the synthesized products were proved by the ¹sH and ¹³C NMR, HMBC, and HSQC (direct proton-carbon correlation) spectra. Dedicated to Academician V. A. Tartakovsky on the occasion of his 75th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1536–1542, August, 2007.