Acetone Anion Research Articles

Syntheses, studies and crystal structure of new coordination polymers of mercury (II) with phenylcyanamide derivative ligands

A series of compounds mercury (II), [Hg(CH2COCH3)L]n where L=anion of 4-NO2pcyd (4-nitro phenylcyanamide) (1), 4-Clpcyd (4-chloro phenylcyanamide) (2), 4-Brpcyd (4-bromo phenylcyanamide) (3) were synthesized from acetone and characterized by elemental analysis, IR, 1H NMR, 13C NMR and electronic absorption spectroscopies. Single crystal X ray analysis of 1 reveals coordination of phenylcyanamide ligand to Hg (II) unexpectedly occurred through amine nitrogen alone which is rare. Also the anion of acetone was coordinated to mercury by the carbon atom as well as oxygen atom from (CO) of another acetone anion. A theoretical study at DFT (B3LYP) level showed that the experimentally determined structure of the complex 1 is about 6.49 and 8.31kcal/mol, respectively in the gas phase and solvent more stable than its other bonding modes. In addition, this phenomenon was supported by NBO interaction energies and the much orbital contribution in the HOMO of ligand to interact with Hg (II) that all of these observations were raised from the presence of nitro group as electron withdrawing group. By using TD-DFT method, electronic absorption spectra of the compound 1 have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. Biological studies show the antibacterial activity of the complex 1 against Gram-positive and Gram-negative bacterial strains.

Syntheses and crystal structures of dinuclear, trinuclear [2 × 1 + 1 × 1] and tetranuclear [2 × 1 + 1 × 2] copper(ii)–d10complexes (d10⇒ ZnII, CdII, HgIIand AgI) derived from N,N′-ethylenebis(3-ethoxysalicylaldimine)

Syntheses, characterization and crystal structures of heterotetranuclear [2 × 1 + 1 × 2] co-crystals [{CuIILZnII(H2O)2}{CuIIL}2](ClO4)2 (1) and [{CuIILCdII(H2O)2(CH3CN)}{CuIIL}2](ClO4)2 (2), dinuclear compound [CuIILHgII(CH2COCH3)](ClO4) (3) and heterotrinuclear [2 × 1 + 1 × 1] co-crystal [{CuIILAgI(H2O)}{CuIIL}](ClO4) (4) derived from N,N′-ethylenebis(3-ethoxysalicylaldimine) (H2L) are reported herein. Compounds 3 and 4 crystallize in the orthorhombic Pbca and monoclinic P21/c systems, respectively, while the space group of compounds 1 and 2 is monoclinic C2/c. The structure of 3 consists of a monophenoxo-bridged CuIIHgII dinuclear core in which the mercury(II) centre is dicoordinated by the bridging phenoxo oxygen atom and the CH2 carbon atom of the mono-deprotonated acetone anion. The coordination environment of HgII in this compound is almost linear. In the CuII2AgI compound 4, one diphenoxo-bridged [CuIILAgI(H2O)]+ cation is co-crystallized with one mononuclear [CuIIL] moieties. On the other hand, the structures of the CuII3MII compounds 1 (M = Zn) and 2 (M = Cd) consist of one diphenoxo-bridged dinuclear CuIIMII unit and two mononuclear [CuIIL] moiety; the composition of the dinuclear unit being [CuIILZnII(H2O)2]2+ and [CuIILCdII(H2O)2(CH3CN)]2+ for 1 and 2, respectively. The AgI (in 4), ZnII (in 1) and CdII (in 2) ions in the diphenoxo-bridged dinuclear cores are tri-, tetra- and heptacoordinated, respectively. The metal ions are coordinated to two bridging phenoxo oxygen atoms, with the silver(I) and zinc(II) centres being additionally coordinated to one and two water molecules, respectively. While in the case of cadmium(II), the additional five coordination positions are occupied by two ethoxy oxygen atoms, two water oxygen atoms and one acetonitrile nitrogen atom. The coordination environment of silver(I) in 4 is pyramidal with a scalene O3 triangle as the base, whereas those of zinc(II) and cadmium(II) in 1 and 2 are distorted tetrahedral and distorted pentagonal bipyramidal, respectively. The coordinated water molecule in 4 and each of the two coordinated water molecules in 1 and 2 are encapsulated into the O4 compartment of a [CuIIL] moiety resulting in the [2 × 1 + 1 × 1] (for 4) or [2 × 1 + 1 × 2] (for 1 and 2) cocrystallization and self-assemblies. Clearly, the encapsulation of the coordinated water molecule(s) is the governing force for the formation of dinuclear-mononuclear co-crystals in 1, 2 and 4. In addition all four compounds 1–4 have π–π stacking interactions which form dimers between pairs of adjacent molecules in the structure of 3 consisting of CuIIHgII dimers, while one-dimensional stacks are formed in the CuII3ZnII (1), CuII3CdII (2) and CuII2AgI (4) complexes. The compositions of the title compounds are compared with the related systems derived from the same ligand. The [2 × 1 + 1 × 1] co-crystal, 4, is a new type of system in terms of the number of components. Again, in spite of the tri-, tetra- and hepta-coordinated nature of the second metal ion in the dinuclear cores, co-crystallization in 1, 2 and 4, respectively, are new observations. The accommodation/coordination of varieties of metal ions by the O4 compartment of H2L has also been highlighted in the present investigation.

Isotope Effects in Dipole-Bound Anions of Acetone

Precision measurements using the Rydberg charge-exchange and electric field-detachment methods find that the dipole-bound electron affinity (EA) of acetone (C3H6O) is 55+/-10 mueV greater than for deuterated acetone (C3D6O). The result agrees well with a theoretical prediction obtained with high-level electronic-structure and anharmonic vibrational calculations. The dipole moments calculated for the vibrationally averaged structures of C3H6O and C3D6O show that the isotope effect (2% reduction) on the EA of acetone is mainly due to a slight reduction (0.5%) of the average dipole moment upon deuteration.

Reactions of halo‐ and dihaloadamantanes with nitromethane anions by the SRN1 mechanism

AbstractThe reactions of 1‐bromo‐, 2‐bromo‐, 1,3‐dibromo‐ and 1,4‐dibromoadamantane with −CH2NO2 anions were studied in DMSO and in liquid ammonia. The photostimulated reaction of 1‐haloadamantane (1‐AdX, X = Br, I) or 2‐AdBr with −CH2NO2 anions gave good yields of the substitution product 1‐AdCH2NO2 and 2‐AdCH2NO2, respectively, in the presence of the enolate anions of acetone (entrainment conditions). On the other hand, 1‐adamantanol was the main product of the reaction performed in DMSO without irradiation, but not in liquid ammonia. 1,3‐Dibromo and 1,4‐dibromoadamantane reacted with −CH2NO2 anions under irradiation in the presence of the enolate anions of acetone. The first compound gave the disubstitution product 11, and the second the monobromo‐substitution products 15 and 16, together with the disubstitution product 17. Compounds 15 and 16 were shown to be intermediates in the formation of 17. Copyright © 2003 John Wiley & Sons, Ltd.

Radiolytic dechlorination of polychlorinated biphenyls using alkaline 2-propanol solutions

Polychlorinated biphenyls (PCBs) were widely used as insulator fluids in electrical equipment, early in the 20th century, but were banned for use about 25 years ago due to their potential toxicity. However, they are still in storage, or present as equipment and soil contaminants, and their safe disposal remains a major challenge. On gamma irradiation in alkaline 2-propanol solutions, PCBs (Arochlor 1254 and 1016) dechlorinate stepwise, giving biphenyl as the ultimate product. Irradiation of alkaline 2-propanol solutions leads to the formation of acetone anion, which transfers electron to PCBs, and partially dechlorinated PCBs, dechlorinating them by one chlorine atom at a time and producing acetone and chloride anion. Acetone, biphenyl and oxygen inhibit the dechlorination of the PCBs. This method has the potential to be used on large scale for the dechlorination of PCBs and PCB-contaminated equipment (capacitors and transformers).

17O NMR spectra of some Meisenheimer adducts

The 17O NMR spectra of 17O isotope-enriched 1,3,5-trinitrobenzene and its Meisenheimer adducts with hydride ion (1), acetone anion (2) and methoxide ion (3) were measured. The adducts 1–3 show 17O signals shifted upfield compared with those of 1,3,5-trinitrobenzene. A higher upfield shift is exhibited by the oxygen atoms of the 4-nitro group (∼90 ppm) and a lower shift by those of the 2- and 6-nitro groups (∼40 ppm). The shift is practically independent of the structure or bulkiness of the nucleophile bound at the tetrahedral centre C1 in the adduct and also, within an experimental error, of the counter ion and solvent (acetonitrile or a mixture of DMSO-d6 and methanol). The measured δ(17O) values indicate that in the Meisenheimer adducts the negative charge at the oxygen atoms is larger in 4-NO2 than in 2- and 6-NO2 groups. Copyright © 2000 John Wiley & Sons, Ltd.

Observation of the dipole-bound excited state of the I−⋅acetone ion-molecule complex

Photofragmentation action spectra of the I−⋅acetone ion-molecule complex reveal the existence of an excited state, located just below the electron detachment threshold, which is thought to correspond to a dipole-bound state derived primarily from the electric dipole moment of acetone. The excited state relaxes by fragmentation into the acetone anion, a dipole-bound ground state anion. This type of excited state should be a general property of ion-molecule complexes, X−⋅M, where M has a significant dipole moment and X does not, and is a microscopic precursor of the charge transfer to solvent bands observed for anions in dipolar solvents.

Absolute stereochemistry of exogonic acid

Exogonic acid (2-(carboxymethyl)-7-methyl-1,6-dioxaspiro[4.4]nonane), a resin constituent of the Brazilian tree Ipomoea operculata (Martin) is demonstrated to be predominantly the E,E and Z,Z diastereomers, with the 2S,5S,7R and 2S,5R,7R configurations, respectively. Minor amounts of the 2R,5S,7R E,Z and 2R,5R,7R Z,E isomers are also present. These conclusions are based on chiral gas chromatographic analyses of suitable derivatives and enantioselective syntheses employing (S)-1,2-epoxypropane and (2S)-4-[[(1,1-dimethylethyl)dimethylsilyl]oxy]-1,2-epoxybutane as alkylating agents for anions of acetone N,N-dimethylhydrazone.

An unsuccessful approach to the framework of the antimalarial, arteether

The hexahydrobenzopyran 7a, prepared using the new acetone anion equivalent 17, reacted with singlet oxygen to produce mixtures containing the dioxetane 6, but in situ treatment with acid failed to generate detectable amounts of 4, an analogue of the antimalarial arteether 3.

Aldol condensation of acetone in the two-phase system solid base-benzene in the presence of benzyltriethylammonium chloride

1. We propose a mechanism for the aldol condensation of acetone in the presence of solid base, explaining the optimum way of forming diacetone alcohol by filling the surface of the base with the diacetone alcohol and acetone anions. 2. Disappearance of the diacetone alcohol from the reaction products after filling the principal centers of the free base was caused by its decomposition under the influence of the acetone anion in the organic phase. 3. The reaction orders for acetone in formation of mesityl oxide and phorone in the presence of solid NaOH are second and third, respectively. 4. We have studied the aldol condensation of acetone in the presence of solid NaOH and benzyltriethylammonium chloride. The formation of diacetone alcohol proceeds in the organic phase as a result of the interaction of the onium alcoholate of diacetone alcohol with acetone, which greatly speeds up the reaction rate. The second order of the reaction with respect to acetone is caused by the limiting step of desorption of the anion of diacetone alcohol inside the organic phase. 5 The role of the benzyldiethylammonium chloride consists of desorption from the surface of the base of the anions of acetone and diacetone alcohol adsorbed on it in the form of ionic pairs, leading to a reduction of the basic properties of the surface of the base.

IR study of isopropanol adsorption on haematite

The IR study shows that isopropanol interacts with haematite at IR beam temperature both as a physisorbed form, hydrogen bonded to basic sites of the surface, and as isopropoxide groups. At 423 K a decomposition of isopropoxide groups produces enolate anions of acetone.

Preparation of enol lactones of 3,5,7-triketo and 3,5,7,9-tetraketo acids by the condensation of 4,6-dimethoxy-2-pyrone with anions of mono- and diketones

Condensation of the anions of acetone, acetophenone, acetylacetone and benzoylacetone with 4,6-dimethoxy-2-pyrone afforded good yields of the corresponding 6 substituted 4-methoxy-2-pyrones which were converted to the 4-hydroxy analogs by demethylation with iodotrimethylsilane.

Sigma complexes in the pyrimidine series. 2. σ Complexes of 5-nitropyrimidine and methoxy-substituted 5-nitropyrimidines with the acetone anion

The corresponding σ complexes of the Meisenheimer type, viz., anions of the potassium salts of 6H-5-nitro-6-acetonylpyrimidines, were obtained and isolated in the reaction of 5-nitro-, 5-nitro-4-methoxy-, 5-nitro-2-methoxy-, and 5-nitro-2,4-dimethoxypyrimidines with acetone in the presence of potassium hydroxide. The structures of the complexes were proved by means of the PMR, IR, and UV spectra. It is shown that the acetone anion in all cases adds to the methoxy-unsubstituted position of the pyrimidine ring, whereas nucleophilic attack takes place at the C4 atom when the 2 and 4 positions are free.

Sigma complexes in the pyrimidine series. 2. σ Complexes of 5-nitropyrimidine and methoxy-substituted 5-nitropyrimidines with the acetone anion

Sigma complexes in the pyrimidine series. 2. σ Complexes of 5-nitropyrimidine and methoxy-substituted 5-nitropyrimidines with the acetone anion

Reactions of carbon nucleophiles with 4‐phenyl‐ and 4‐tert‐butyl‐5‐halogenopyrimidines. On the occurrence of an SRN1 mechanism

AbstractReaction of 5‐X‐4‐phenylpyrimidine (X = Br, Cl) with the enolate anions of acetone and acetophenone in liquid ammonia yields 5‐acetonyl‐ and 5‐phenacyl‐4‐phenylpyrimidine, respectively. It is shown that these reactions proceed via an SRN1 mechanism. Reaction of 5‐X‐4‐phenylpyrimidine (X = Br, Cl) with the enolate anion of pinacolone gives besides SRN1 substitution, addition of the anion to the N(1)‐C(6)‐azomethine bond. On treatment of 5‐X‐4‐tert‐butylpyrimidine with the enolate anions of acetone, acetophenone or pinacolone, substitution products are formed in very low yields. Addition of potassium to the liquid ammonia or irradiation with near ultraviolet light, however, increases the yields of 5‐substituted 4‐tert‐butylpyrimidine derivatives considerably.