One-Pot Solvent-and Catalyst-Free Synthesis of Some New Heteroarylaminonaphthoquinones from Lawsone

: A clean and efficient one-pot protocol for the synthesis of a series of new 2-hydroxy-3-((3-aryl)(heteroarylamino)methyl)naphthalene-1,4-dione derivatives has been developed by the three-component reaction of 2-hydroxynaphthalene-1,4-dione, aromatic aldehydes and heterocyclic amines at 90 oC under solvent and catalyst-free conditions. The procedure avoids the use of toxic solvents, tedious work-up, catalyst and purification of the products by chromatographic methods. Simple operation, short reaction times, generating the desired compounds in high to excellent yields and an environmentally benign method are advantages of this protocol.

Insights into Selection of the Auxiliary Collector and Its Applicability Analysis for Improving Molybdenite Flotation

In this study, two auxiliary collectors (methyl naphthalene and naphthalene) of molybdenite and the traditional collector (kerosene) were mixed for molybdenite flotation, respectively. According to the selection and analysis of the auxiliary collector, it was found that the surface energy (γC= 4.50 mJ/m2) of the polycyclic aromatic hydrocarbons is very close to that (γS= 42.55 mJ/m2) of the molybdenite {100} surface. Therefore, it can be physically adsorbed onto the molybdenite {100} surface according to the principle of similar compatibility. Batch flotation was conducted on actual ore with the mixed collector, compared with kerosene alone. Batch flotation results showed that the mixed collector at a mass ratio of 95:5 of main collector to auxiliary collector at pH 11.0 improved molybdenite flotation, that is, the Mo recovery was increased by 3–4%. The practical application feasibility of the auxiliary collector was analyzed by the filtration speed of the flotation concentrate and the crystal resolution characteristics of the auxiliary collector. The results show that solid naphthalene (Nap) is easy to crystallize at low temperature and adhere to the surface of the flotation concentrate, resulting in a decrease of filtration velocity, while liquid methylnaphthalene (MNap) does not crystallize at low temperature. These results imply that the mixed collector Kerosene/MNap can generate a superior synergistic effect and achieve better collecting capacity than kerosene alone, resulting in the increase of flotation recovery by 3–4 percentage points. Moreover, the addition of MNap has little negative impact on the subsequent treatment of the product.

New, highly versatile bimolecular photoinitiating systems for free-radical, cationic and thiol–ene photopolymerization processes under low light intensity UV and visible LEDs for 3D printing application

1-Amino-4-methyl-naphthalene-2-carbonitrile derivatives are proposed for the role of photosensitizers of iodonium salt during the photopolymerization processes upon near UV-A and visible ranges.

Ba-Ni-Hexaaluminate as a New Catalyst in the Steam Reforming of 1-Methyl Naphthalene and Methane

This work investigates the long-term performance of Ba-Ni-hexaaluminate, BaNixAl12−xO19 as a catalyst in reforming of 1-methyl naphthalene and/or methane in a model-gas simulating that from a circulating fluidized bed (CFB) gasifier during 23–29 h in a lab scale set-up, as well as the tendency for coke formation, sintering and sulphur poisoning. 1-Methyl naphthalene is used as a tar model substance. The Ba-Ni-hexaaluminate induces a high conversion of both compounds in the temperatures investigated (850 and 950 °C) under sulphur-free conditions. In sulphur-containing gas, the methane conversion stops at 20 ppm H2S and the reforming of 1-MNP at 850 °C is slightly reduced at 100 ppm. Graphic Abstract

Preparation, Spectroscopic Characterization and Theoretical Studies of Transition Metal Complexes with 1-[(2-(1H-indol-3-yl)ethylimino)methyl]naphthalene-2-ol Ligand

A new Schiff base [1-((2-(1H-indol-3-yl)ethylimino)methyl)naphthalene-2-ol] (HL) has been synthesized by condensing (2-hydroxy-1-naphthaldehyde) with (2-(1H-indol-3-yl)ethylamine). In turn, its transition metal complexes were prepared having the general formula; [Pt(IV)Cl2(L)2], [Re(V)Cl2(L)2]Cl and [Pd(L)2], 2K[M(II)Cl2(L)2] where M(II) = Co, Ni, Cu] are reported. Ligand as well as metal complexes are characterized by spectroscopic techniques such as FT-IR, UV-visible, 13C & 1H NMR, mass, elemental analysis. The results suggested that the ligand behaves like a bidentate ligand for all the synthesized complexes. On the other hand, theoretical studies of the ligand as well its metal complexes were conducted at gas phase using HyperChem 8.0. These metal complexes exhibited good antibacterial activity.