The Structures,Morphologies, and Photophysical Properties of Multiluminescent Layered Lanthanide–Phosphono–Carboxylate Nanoparticles

A new family of layered metal(III)–phosphono–carboxylate nanostructures (M=Y, Eu, Tb, Er, and Yb) was hydrothermally synthesized and their structures and morphologies were characterized by X‐ray powder diffraction and TEM. 4‐[Bis(phosphonomethyl)amino]caproic acid and 4‐ [bis(phosphonomethyl)amino]undecan‐ oic acid, with general formula (H₂O₃PCH₂)₂NR (R=C₅H₁₀COOH (P2CAPR) and C₁₀H₂₂COOH (P2UND), respectively) were used as building blocks for the preparation of novel layered hybrid materials in which the inorganic layers were composed of MO₇ or MO₈ polyhedra and PO₃C tetrahedra. The interlayer region was occupied by carboxyalkyl chains. These layered compounds were easily dispersed as stable solutions in alkylamine/water upon ultrasonication. These dispersions were constituted of rectangular elongated nanoparticles (NPs), which showed a distribution of sizes ranging from 20–500 nm. These new materials had interesting photophysical properties because they were multiluminescent compounds. These properties gave rise to several emission bands, which were spread over the broad spectroscopic region, from the near‐UV up to the near‐IR regions. Each emission band had a specific lifetime, which ranged from the sub‐ps to the ms scale.     

Metal aminocarboxylate coordination polymers with chain and layered structures

The synthesis and structures of metal aminocarboxylates prepared in acidic, neutral, or alkaline media have been explored with the purpose of isolating coordination polymers with linear chain and two-dimensional layered structures. Metal glycinates of the formulae [CoCl2(H2O)2(CO2CH2NH3)] (I), [MnCl2(CO2CH2NH3)2] (II), and [Cd3Cl6(CO2CH2NH3)4] (III) with one-dimensional chain structures have been obtained by the reaction of the metal salts with glycine in an acidic medium under hydro/solvothermal conditions. These chain compounds contain glycine in the zwitterionic form. 4-Aminobutyric acid transforms to a cyclic amide under such reaction conditions, and the amide forms a chain compound of the formula [CdBr2(C4H7NO)2] (IV). Glycine in the zwitterionic form also forms a two-dimensional layered compound of the formula [Mn(H2O)2(CO2CH2NH3)2]Br2 (V). 6-Aminocaproic acid under alkaline conditions forms layered compounds with metals at room temperature, the metal being coordinated both by the amino nitrogen and the carboxyl oxygen atoms. Of the two layered compounds [Cd{CO2(CH2)5NH2}2]2 H2O (VI) and [Cu{CO2(CH2)5NH2}2]2 H2O (VII), the latter has voids in which water molecules reside.     

Stereoisomeric Pd(II) complexes with serine,threonine, and allothreonine

The paper describes methods for the synthesis and isolation of solid phases of the individual stereoisomeric Pd(II) bis(amino acid) complexes with serine (SerH = NH₂C*H(CH₂OH)COOH, α-amino-β-hydroxypropionic acid), threonine (ThrH CH₃C*H(OH)C*H(NH₂)COOH, threo-α-amino-β-hydroxybutyric acid), and allothreonine (alloThrH is erythro-α-amino-β-hydroxybutyric acid): cis-[Pd(S-Ser)2], trans-[Pd(R-Ser)(S-Ser)], cis-[Pd(S-Thr)₂], trans-[Pd(S-Thr)₂], trans-[Pd(R-Thr)(S-Thr)], and cis-[Pd(R-alloThr)(S-alloThr)] (R, S are the absolute configurations of the asymmetric C* atom connected to the NH₂ group). The synthesized compounds were characterized by elemental analysis, IR and NMR (¹H and ¹³C) data, and X-ray diffraction analysis.     

High-throughput investigation and characterization of cobalt carboxy phosphonates

High-throughput methods have been employed to study the system Co(2+)/(H(2)O(3)PCH(2))(2)NCH(2)C(6)H(4)COOH/NaOH in detail. The use of the phosphonocarboxylic acid (H(2)O(3)PCH(2))(2)NCH(2)C(6)H(4)COOH has led to several new cobalt carboxyaryl phosphonates under hydrothermal conditions. In addition to the effect of the pH of the starting mixture, the influence of the counterions of the cobalt salts on the product formation was investigated. Thus, reaction trends as well as fields of formation could be identified. Four new compounds Co(2)[(O(3)PCH(2))(2)NCH(2)C(6)H(4)COOH].H(2)O (1), Co[(O(3)PCH(2))(OCH)NCH(2)C(6)H(4)COOH].H(2)O (2), Co[H(2)(O(3)PCH(2))(2)NCH(2)C(6)H(4)COOH] (3), and [Co(2)(O(3)PCH(2))(2)NCH(2)C(6)H(4)COOH].3.5H(2)O (4) were obtained, and compounds 1 and 2 could be isolated as single crystals suitable for single-crystal X-ray diffraction. The counterions of the cobalt salts have an influence on the structure of the resulting compounds. This is due to the effect on the initial pH as well as the possibility of the counterions to take part in redox reactions. Compounds 1 and 4 are formed under more basic conditions, and the phosphonic acid group is fully deprotonated. The structure of 1 is a rare example of the family of inorganic-organic hybrid materials with iminobis(methylphosphonic acid) units wherein the nitrogen coordinates to the metal center. Compound 2 is the result of an in situ oxidation of one of the P-C bonds; the organic building unit is stabilized by complexation of the cobalt ion. On the basis of spectroscopic, thermogravimetric, elemental chemical analysis, and EDX-analysis data, compound 3 has been characterized as Co[H(2)(O(3)PCH(2))(2)NCH(2)C(6)H(4)COOH] and compound 4 as [Co(2)(O(3)PCH(2))(2)NCH(2)C(6)H(4)COOH].3.5H(2)O. X-ray powder diffraction and IR-spectroscopic studies show that thermal treatment of 4 leads to the title compound 1. This transformation is accompanied by a change of color from pink to deep blue.     

New layered rare-earth hydroxides with anion-exchange properties

We report the synthesis of a new series of layered hydroxides based on rare-earth elements with a composition of RE(OH)2.5Cl(0.5).0.8 H2O (RE: Eu, Tb, etc.) through the homogeneous precipitation of RECl3.x H2O with hexamethylenetetramine (HMT). Rietveld analysis combined with direct methods revealed an orthorhombic layered structure comprising a positively charged layer of [RE(OH)2.5-(H2O)0.8]0.5+ and interlayer Cl- ions. The Cl- ions were readily exchangeable for various anions (NO3-, SO4(2-), dodecylsulfonate, etc.) at ambient temperature. Photoluminescence studies showed that the compounds display typical RE3+ emission. With rare-earth-based host layers and tunable interlayer guests, the new compounds may be of interest for optoelectronic, magnetic, catalytic, and biomedical materials.     

Synthesis, structure and optical properties of rare-earth benzene carboxylates

Two series of rare-earth isophthalates of the general formula, [M(2)(H(2)O)][{C(6)H(4)(COO)(2)}(2){C(6)H(4)(COOH)(COO)}(2)].H(2)O, M=La (I), Pr (Ia), and Nd (Ib) and [M(2)(H(2)O)(2)][{C(6)H(4)(COO)(2)}(3)].H(2)O, M=Y (II), Gd (IIa), and Dy (IIb) have been prepared by the reaction of the corresponding trivalent lanthanide salts and isophthalic acid under mild hydrothermal conditions. The La (I), Pr (Ia) and Nd (Ib) have MO(9) polyhedra connected to the isophthalate anions forming a two-dimensional structure, whereas Y (II), Gd (IIa) and Dy (IIb) have MO(7) and MO(8) polyhedral units connected to the isophthalate anions forming a different, but related two-dimensional structure. Both the structures are stabilized by hydrogen bonding and pi...pi/CH...pi interactions. Partial substitution of Eu and Tb (2 and 4%) at the La (I) and Y (II) sites give rise to characteristic red/pink or green luminescence, indicating a ligand-sensitized metal-centered emission. The Nd (Ib) compound shows interesting UV and blue emission through an up-conversion process.     

Syntheses, structure, and derivatization of potassium complexes of penta(organo)[60]fullerene-monoanion, -dianion, and -trianion into hepta- and octa(organo)fullerenes

Two-electron reduction of penta(organo)[60]fullerenes C(60)Ar(5)H (Ar = Ph and biphenyl) by potassium/mercury amalgam afforded potassium complexes of the corresponding open-shell radical dianions [K+(thf)n]2[C60Ar5(2-.)]. These compounds were characterized by UV-visible-near-IR and electron spin resonance spectroscopy in solution. Anaerobic crystallization of [K+(thf)n]2[C60(biphenyl)(5)(2-.)] that exists largely as a monomer in solution gave black crystals of its dimer [K+(thf)3]4[(biphenyl)5C60-C60(biphenyl)5(4-)], in which the two fullerene units are connected by a C-C single bond [1.577(11) A] as determined by X-ray diffraction. Three-electron reduction of C60Ar5H with metallic potassium gave a black-green trianion [K+(thf)n]3[C60Ar5(3-)]. The reaction of the trianion with an alkyl halide RBr (R = PhCH(2) and Ph(2)CH) regioselectively afforded a hepta-organofullerene C60Ar5R2H, from which a potassium complex [K+(thf)n][C60(biphenyl)5(CH2Ph)(2)(-)] and a palladium complex Pd[C60(biphenyl)5(CH2Ph)2](pi-methallyl) as well as octa-organofullerene compounds C60(biphenyl)5(CH2Ph)3H2 and Ru[C60(biphenyl)5(C2Ph)3H]Cp were synthesized. These compounds possess a dibenzo-fused corannulene pi-electron conjugated system and are luminescent.     

Tunable supramolecular synthons and versatile, water-soluble building blocks for crystal engineering:

It is shown that the water-soluble dicarboxylic cationic acid [(eta5-C5H4COOH)2Co(III)]+ (1) is an extremely versatile building block for the construction of organometallic crystalline edifices. Removal of one proton from 1 leads to formation of the neutral zwitterion [(eta5-C5H4COOH)(eta5-C5H4COO)Co(III)] (2), while further deprotonation leads to formation of the dicarboxylate monoanion [(eta5-C5H4COO)2Co(III)]- (3). Compounds 1. 2 and 3 possess different hydrogen-bonding capacity and participate in a variety of hydrogen-bonding networks. The cationic form 1 has been characterised as its [PF6]- and Cl- salts 1-[PF6] and 1-Cl.H2O, as well as in its co-crystal with urea, 1-Cl.3(NH2)2CO, and with the zwitterionic form 2, [(eta5-CH4COOH)(eta5-C5H4COO)Co(III)][(eta5-C5H4COOH)2Co(III)]+[PF6]-, 2.1-[PF6]. The neutral zwitterion 2 behaves as a supramolecular crown ether: it encapsulates the alkali cations K+, Rb+ and Cs+ as well as the ammonium cation NH4+ in cages sustained by O-H...O and C-H...O hydrogen bonds to form co-crystalline salts of the type 2(2)-M[PF6] (M = K, Rb, Cs) and 2(2)-[NH4][PF6]. The deprotonated acid 3 has been characterised as its Cs+ salt, Cs+-3.3H2O.     

混合型甘氨酸-N，N-双亚甲基膦酸-磷酸锆：合成、表征及插层

采用氢氟酸络合法,在nP/nZr=2.0条件下,以甘氨酸-N,N-双亚甲基膦酸(DMPG)和H3PO4为原料,按不同投料物质的量的比制备了2个α、γ-混合型甘氨酸-N,N-双亚甲基膦酸-磷酸锆层状主体化合物Zr(PO4)0.41(HPO4)0.043[(O3PCH2)2NCH2COOH]0.67.H2O(1)和Zr(PO4)0.21(HPO4)0.038[(O3PCH2)2NCH2COOH]0.82.2H2O(2),用元素分析、X射线衍射、红外光谱、热分析、固体核磁磷谱等对化合物进行了表征,同时研究了与正丁胺客体分子的插层组装性能。     

Synthesis,structural and spectroscopic properties of two new ethylenediamine-templated gallophosphate-oxalate layered materials

Two new layered gallophosphate-oxalate materials have been prepared hydrothermally using ethylenediamine and oxalic acid as structure-directing agents. The compounds (C2N2H10)2[Ga2(C2O4)2(HPO4)3].H2O 1 and (C2N2H10)3- [Ga4(C2O4)4(HPO4)4(H2PO4)2] 2 are closely related, consisting of anionic double chains built of alternating paris of GaO6 and HPO4 polyhedra. These double chains are linked via bridging HPO4 or H2PO4 tetrahedra to form corrugated layers containing eight-membered rings. The oxalate group acts as a bidentate ligand to each of the GaO6 octahedron. The corrugated layers are held together by strong to weak hydrogen-bonding interactions between oxalate groups, water and diprotonated ethylenediamine molecules, and the framework components. The compounds were characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and infrared and Raman spectroscopy. Crystal data for 1: monoclinic, space group P21/C (No. 14), a = 6.355(1) A, b = 39.362(8) A, c = 9.249(2) A, beta = 106.7(1) degrees, Z = 2. Crystal data for 2: triclinic, space group P1 (No. 2), a = 8.730(1) A, b = 11.575(1) A, c = 11.696(1) A, alpha = 115.12(1) degree, beta = 90.07(1) degree, gamma = 111.23(1) degree, Z = 2.     

Fragmentation of the deprotonated ions of peptides containing cysteine, cysteine sulfinic acid, cysteine sulfonic acid, aspartic acid, and glutamic acid

We examined the fragmentation of the electrospray-produced [M-H]- and [M-2H]2- ions of a number of peptides containing two acidic amino acid residues, one being aspartic acid (Asp) or glutamic acid (Glu), and the other being cysteine sulfinic acid [C(SO2H)] or cysteine sulfonic acid [C(SO3H)], on an ion-trap mass spectrometer. We observed facile neutral losses of H2S and H2SO2 from the side chains of cysteine and C(SO2H), respectively, whereas the corresponding elimination of H2SO3 from the side chain of C(SO3H) was undetectable for most peptides that we investigated. In addition, the collisional activation of the [M-H]- ions of the C(SO2H)-containing peptides resulted in the cleavage of the amide bond on the C-terminal side of the C(SO2H) residue. Moreover, collisional activation of the [M-2H]2- ions of the above Asp-containing peptides led to the cleavage of the backbone N-Calpha bond of the Asp residue to give cn and/or its complementary [zn-H2O] ions. Similar cleavage also occurred for the singly deprotonated ions of the otherwise identical peptides with a C-terminal amide functionality, but not for the [M-H]- ions of same peptides with a free C-terminal carboxylic acid. Furthermore, ab initio calculation results for model cleavage reactions are consistent with the selective cleavage of the backbone N-Calpha bond in the Asp residue.     

Carbidohexarhenate cluster cores bicapped by mercury with acetate or thiolate ligands

The reaction of [PPh4]3[Re7C(CO)21] (1) with 1 or more equiv of Hg(OAc)2 in dichloromethane provides the monomercury derivative [PPh4]2[Re7C(CO)21HgOAc] (2) in high yield. However, in the presence of methanol the reaction of 1 with 2 equiv of Hg(OAc)2 yields the dimercury hexarhenium cluster compound [PPh4]2[Re6C(CO)18(HgOAc)2] (3) together with the dirhenium complex [PPh4][Re2(CO)6(mu-OMe)2(mu-OAc)] (4). The dimercury compound 3 reacts with various thiols HS-Z to form thiolate-substituted derivatives [PPh4]2[Re6C(CO)18(HgSZ)2] [Z = C6H4Br (5); C5H4N (6); C2H4COOH (7)]. All new compounds have been characterized by a combination of analytical and spectroscopic data, and the molecular structures of compounds 3-6 have been determined by X-ray crystallography.     

The influence of phosphane coligands on the nuclearity of rhodium(I) 4-thiolatobenzoic acid complexes

[RhCl(PR3)3] (R = Ph, Et) reacts with the potassium salt of 4-mercaptobenzoic acid to give a mixture of the monomeric and dimeric complexes, [Rh(SC6H4COOH)(PR3)3] and [{Rh(-SC6H4COOH)(PR3)2}2], respectively. With the labile PPh3 coligand, the dimer is the major product, while for the electron-richer coligand PEt3, the equilibrium is easily shifted to the monomer by the addition of excess PEt3. Phosphane dissociation and dimerization could be prevented by using the chelating coligand PPh(C2H4PPh2)2. [{Rh(-SC6H4COOH)(PPh3)2}2] (2b), [Rh(SC6H4COOH)(PEt3)3] (3a), and [Rh(SC6H4COOH){PPh(C2H4PPh2)2}] (4) were fully characterized by nuclear magnetic resonance and infrared spectroscopy, mass spectrometry, and elemental analysis. The molecular structures of 2b and 4 were determined by X-ray structure analysis. In solution, the lability of the phosphane ligands leads to the decomposition of 2b. One of the decomposition products, namely, the mixed-valent complex [{RhIRhIII(-SC6H4COO)(-SC6H4COOH)(SC6H4COOH)(PPh3)3}2] (5), was characterized by X-ray structural analysis. The dinuclear rhodium(III) complex [{Rh(-SC6H4COO)(SC6H4COOH)(PEt3)2}2] (6) was shown to be a byproduct in the synthesis of 3a, and this demonstrates the reactivity of the rhodium(I) complexes toward oxidative addition. The structurally characterized complexes 2b, 4, 5, and 6 show hydrogen bonding of the free carboxyl groups.     

Synthesis, structure, luminescence, and theoretical studies of tetranuclear gold clusters with phosphinocarborane ligands

Treatment of the tetranuclear gold cluster [Au4((PPh2)2C2B9H10)2(AsPh3)2] (1), which contains the nido-carborane-diphosphine [7,8-(PPh2)2C2B9H10]-, with various tertiary phosphines leads to derivatives [Au4((PPh2)2C2B9H10)2-(PR3)2] (PR3 = PPh3 (2), P(4-MeC6H4)3 (3), P(4-OMeC6H4)3 (4)). The X-ray crystal structure of complex 4 shows a tetrahedral framework of gold atoms, two of which are chelated by the diphosphine, and two are coordinated to one monophosphine ligand each. These compounds are very stable and are obtained in high yield. MP2 calculations suggest that the two types of chemically nonequivalent gold atoms can be formally assigned as Au(I) (those attached to the arsines or phosphines) and Au(0) (those bonded to the anionic diphosphine) and emphasize the role of correlation in the gold-gold interactions. The compounds are luminescent. The emission is assigned to a gold-centered spin-forbidden transition; the assignment of the oxidation state of the gold centers on this basis leads to results coincident with those obtained by theoretical calculations.     

Rational design and synthesis of porous organic-inorganic hybrid frameworks constructed by 1,3,5-benzenetriphosphonic acid and pyridine synthons

1,3,5-Benzenetriphosphonic acid, H6BTP, 1,3,5-[(HO)2OP]3C6H3, was reacted hydrothermally with copper salts in the absence and presence of 4,4'-bipyridine (bpy) and 4,4'-trimethlyenedipyridine (tbpy) in a 1:1 molar ratio leading to three new organic-inorganic hybrid frameworks. Compound 1, {Cu6[C6H3(PO3)3]2(H2O)8} x 5.5 H2O, has three different copper ions that are interconnected by the highly charged [1,3,5-(PO3)3C6H3]6- anionic moieties. These moieties self-assemble through tetra-copper units to give a cagelike motif with two benzene rings parallel to each other at a distance of 3.531 A which extend along the a axis and link with a grouping of four-coordinated copper units in the b axis direction to give the cross-linked layered structure. In compound 2, Cu{C6H3[PO(OH)O]2[PO(OH)2]}(C10H8N2), the copper ions are in square pyramidal geometries and are interconnected via chelating and bridging BTP ligands into layers which are further cross-linked by bpy ligands into a pillared layered architecture. Compound 3, {Cu2C6H3[PO(OH)O]2[PO3](C13H14N2)} x 3 H2O x 0.5 HCON(CH3)2, contains tetra-copper units that are linked by BTP ligands and further linked by tbpy linkers in the c axis direction to produce a large channel-sized 3D framework.     

A novel ligand-free palladium catalytic system with SO3H-functional ionic liquids as cocatalyst for amidocarbonylation reaction

Effects of Lewis acid BF3·OEt2, and BrCnsted acids TsOH, CF3COOH, H3PO4, and HCIO4 as cocatalyst respectively on the ligand-free palladium-catalyzed amidocarbonylation were investigated. SO3H-functional ionic liquids 1-methyl-3-（4-sulfonic acid）butylimidazolium hydrosulfate [MIm（CH2）4803H][HSO4] and 1-methyl-3-（4-sulfonic acid）butylimidazolium triflate [MIm（CH2）4SO3H][OTf] were firstly employed as cocatalysts instead of these Lewis acid and Brφnsted acids. By using a ligand-free and weak corrosive catalyst in situ prepared form PdBr2, LiBr.H2O, and [MIm（CH2）4SO3H][OTf], the arnidocarbo- nylation of benzaldehyde, acetamide, and CO could proceed smoothly and afford N-acetyl-α-phenylglycine with yield of 58% in [C6mim]PF6 medium.     

Energetics of C-Cl, C-Br, and C-I bonds in haloacetic acids: enthalpies of formation of XCH2COOH (X=CI, Br, I) compounds and the carboxymethyl radical

The standard molar enthalpies of formation of chloro-, bromo-, and iodoacetic acids in the crystalline state, at 298.15 K, were determined as deltafH(o)m(C2H3O2Cl, cr alpha)=-(509.74+/- 0.49) kJ x mol(-1), deltafH(o)m(C2H3O2Br, cr I)-(466.98 +/- 1.08) kJ x mol(-1), and deltafH(o)m (C2H3O2I, cr)=-(415.44 +/- 1.53) kJ x mol(-1), respectively, by rotating-bomb combustion calorimetry. Vapor pressure versus temperature measurements by the Knudsen effusion method led to deltasubH(o)m(C2H3O2Cl)=(82.19 +/- 0.92) kJ x mol(-1), deltasubH(o)m(C2H3O2Br)=(83.50 +/- 2.95) kJ x mol(-1), and deltasubH(o)m-(C2H3O2I) = (86.47 +/- 1.02) kJ x mol(-1), at 298.15 K. From the obtained deltafH(o)m(cr) and deltasubH(o)m values it was possible to derive deltafH(o)m(C2H3O2Cl, g)=-(427.55 +/- 1.04) kJ x mol(-1), deltafH(o)m (C2H3O2Br, g)=-(383.48 +/- 3.14) kJ x mol(-1), and deltafH(o)m(C2H3O2I, g)=-(328.97 +/- 1.84) kJ x mol(-1). These data, taken with a published value of the enthalpy of formation of acetic acid, and the enthalpy of formation of the carboxymethyl radical, deltafH(o)m(CH2COOH, g)=-(238 +/- 2) kJ x mol(-1), obtained from density functional theory calculations, led to DHo(H-CH2COOH)=(412.8 +/- 3.2) kJ x mol(-1), DHo(Cl-CH2COOH)=(310.9 +/- 2.2) kJ x mol(-1), DHo(Br-CH2COOH)=(257.4 +/- 3.7) kJ x mol(-1), and DHo(I-CH2COOH)=(197.8 +/- 2.7) kJ x mol(-1). A discussion of the C-X bonding energetics in XCH2COOH, CH3X, C2H5X, C2H3X, and C6H5X (X=H, Cl, Br, I) compounds is presented.     

O2结构Liy[Mn1—xMx]O2（M＝Cr，Mg）的合成及结构研究

由高温焙烧法制备层状前驱体Na_(2/3)[Mn_(1-x)M_x]O_2（M＝Cr, Mg），再 经离子交换反应得到层状O2结构产物Li_y-[Mn_(1-x)M_x]。XRD表明Li_y[Mn_(1-x) M_x]O_2属六方晶系，P3ml空间群。Cr的添加量对前驱体的晶体结构有很大影响： 随着x值的增大，前驱体逐渐由层状P2结构Na_(2/3)[Mn_(1-x)Cr_x]O_2向正交结构 Na_4Mn_90_(18)转变。由SEM可以看到样品Li_y[Mn_(1-x)Cr_x]-O_2(x≤0.05)具有 六方层状结构。XPS分析结果表明样品Li_y[Mn_(0.95)Cr_(0.05)]O_2表面上的Mn和 Cr分别以Mn~(4+)存在，并且表面中Cr相对含量高于体相，而样品Li_y[Mn_(0.90) Mg_(0.10)]O_2的表面Mn和Mg分别以Mn~(4+)和Mg~(2+)存在，Mg/Mn比在表面与体相 基要一致。     

Bis coumarinyl bis triazolothiadiazinyl ethane derivatives: Synthesis,antiviral activity evaluation,and molecular docking studies

A series of novel 3,3′-(3,3′-(dihydroxy/hydroxyethane-1,2-diyl)bis(7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-6,3-diyl))bis(2H-chromen-2-ones) were prepared by the condensation of thiocarbohydrazide with tartaric acid or malic acid followed by various 3-(2-bromoacetyl)-2H-chromen-2-ones in two steps with good yields. All the synthesized compounds were characterized by analytical and spectral (IR, ¹H NMR, ¹³C NMR, and mass) data. These synthesized bis(triazolothiadiazinyl coumarin) compounds were evaluated for broad spectrum of antiviral activity. Among all the tested compounds, compound 5f exhibited antiviral activity against H1N1 virus. The molecular docking studies of these compounds against H1N1 neuraminidase enzyme were performed. The binding affinity and binding values were compared with standard drugs.     

Monocarbaborane anion chemistry. [COOH], [CH2OH] and [CHO] units as functional groups on ten-vertex monocarbaborane anionic compounds

B(10)H(14) reacts with para-C(6)H(4)(CHO)(COOH) in aqueous KOH solution to give the [nido-6-CB(9)H(11)-6-(C(6)H(4)-para-COOH)](-) anion 1, which undergoes cage closure with iodine in alkaline solution to give the [closo-2-CB(9)H(9)-2-(C(6)H(4)-para-COOH)](-) anion 2. Upon heating, anion 2 rearranges to form the [closo-1-CB(9)H(9)-1-(C(6)H(4)-para-COOH)](-) anion 3. Similarly, B(10)H(14) with glyoxylic acid OHCCOOH in aqueous KOH gives the [arachno-6-CB(9)H(13)-6-(COOH)](-) anion 4, which undergoes cage closure with iodine in alkaline solution to give the [closo-2-CB(9)H(9)-2-(COOH)](-) anion 5. Upon heating, anion 5 rearranges to give the [closo-1-CB(9)H(9)-1-(COOH)](-) anion 6. Reduction of the [COOH] anions 3 and 6 with diisobutylaluminium hydride gives the [CH(2)OH] hydroxy anions [closo-1-CB(9)H(9)-1-(C(6)H(4)-para-CH(2)OH)](-) and [closo-1-CB(9)H(9)-1-(CH(2)OH)](-) 8 respectively. The [closo-1-CB(9)H(9)-1-(C(6)H(4)-para-CH(2)OH)](-) anion 7 can also be made via isomerisation of the [closo-2-CB(9)H(9)-2-(C(6)H(4)-para-CH(2)OH)](-) anion 9, in turn obtained from the [nido-6-CB(9)H(11)-6-(C(6)H(4)-para-CH(2)OH)](-) anion 10, which is obtained from the reaction of B(10)H(14) with terephthaldicarboxaldehyde, C(6)H(4)-para-(CHO)(2), in aqueous KOH solution. Oxidation of the hydroxy anions 7 and 8 with pyridinium dichromate gives the aldehydic [closo-1-CB(9)H(9)-1-(C(6)H(4)-para-CHO)](-) anion 11 and the aldehydic [closo-1-CB(9)H(9)-1-(CHO)](-) anion 12 respectively, characterised as their 2,4-dinitrophenylhydrazone derivatives, the [closo-1-CB(9)H(9)-1-C(6)H(4)-para-CH=N-NHC(6)H(3)(NO(2))(2)](-) anion 13 and the [closo-1-CB(9)H(9)-1-CH=N-NHC(6)H(3)(NO(2))(2)](-) anion respectively.