Dioxygen splitting at room temperature over distant binuclear transition metal centers in zeolites for direct oxidation of methane to methanol

The room-temperature operation of a methane-based photo-fuel cell is demonstrated for the first time. This is achieved using a TiO2 nanotube arrays photoanode which shows effective oxidation of methane.

Download Full-text

Transition Metal-Free Intramolecular Friedel-Crafts Reaction by Alkene Activation: A Method for the Synthesis of Some Novel Xanthene Derivatives

10.3762/bxiv.2021.40.v1 ◽

2021 ◽

Author(s):

Tülay Yıldız ◽

İrem Baştaş ◽

Hatice Başpınar Küçük

Keyword(s):

Transition Metal ◽

Trifluoroacetic Acid ◽

Room Temperature ◽

Synthesis Method ◽

Biological Significance ◽

Metal Free ◽

New Synthesis ◽

Starting Point ◽

Xanthene Derivatives ◽

First Time

In this work, new derivatives (substituted 9-methyl-9-arylxanthenes) of xanthene compounds (5a-5l) of possible biological significance were synthesized by developing a new synthesis method. In order to obtain xanthene derivatives, the original alkene compounds to be used as the starting point were synthesized in four steps using appropriate reactions. Cyclization reaction by intramolecular Friedel-Crafts alkylation was carried out in order to synthesize the desired xanthene derivatives using the alkenes as starting compounds. Intramolecular Friedel-Crafts reaction was catalyzed by trifluoroacetic acid (TFA) and provided some novel substituted 9-methyl-9-arylxanthenes with good yields at room temperature within 6–24 hours. As a result, an alkene compound was used for activation with TFA in the synthesis of xanthene through intramolecular Friedel-Crafts alkylation for the first time.

Download Full-text

Transition-metal-free intramolecular Friedel–Crafts reaction by alkene activation: A method for the synthesis of some novel xanthene derivatives

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.17.142 ◽

2021 ◽

Vol 17 ◽

pp. 2203-2208

Author(s):

Tülay Yıldız ◽

İrem Baştaş ◽

Hatice Başpınar Küçük

Keyword(s):

Transition Metal ◽

Trifluoroacetic Acid ◽

Room Temperature ◽

Synthesis Method ◽

Biological Significance ◽

Cyclization Reaction ◽

Metal Free ◽

New Synthesis ◽

Xanthene Derivatives ◽

First Time

In this work, new derivatives (substituted 9-methyl-9-arylxanthenes) of xanthene compounds (5a–l) of possible biological significance were synthesized by developing a new synthesis method. In order to obtain xanthene derivatives, the original alkene compounds to be used as the starting materials were synthesized in four steps using appropriate reactions. A cyclization reaction by intramolecular Friedel–Crafts alkylation was carried out in order to synthesize the desired xanthene derivatives using the alkenes as starting compounds. The intramolecular Friedel–Crafts reaction was catalyzed by trifluoroacetic acid (TFA) and provided some novel substituted 9-methyl-9-arylxanthenes with good yields at room temperature within 6–24 hours. As a result, an alkene compound was used for activation with TFA in the synthesis of xanthene through intramolecular Friedel–Crafts alkylation for the first time.

Download Full-text

Methane activation by ZSM-5-supported transition metal centers

Chemical Society Reviews ◽

10.1039/d0cs01016b ◽

2021 ◽

Author(s):

Daniyal Kiani ◽

Sagar Sourav ◽

Yadan Tang ◽

Jonas Baltrusaitis ◽

Israel E. Wachs

Keyword(s):

Transition Metal ◽

Methane Activation ◽

Group V ◽

Metal Centers ◽

Methane Dehydroaromatization

The literature on methane dehydroaromatization (MDA) to benzene using ZSM-5 supported, group V–VIII transition metal-based catalysts (MOx/ZSM-5) is critically reviewed with a focus on in situ and operando molecular insights.

Download Full-text

Room-temperature white and color-tunable afterglow by manipulating multi-mode triplet emissions

Journal of Materials Chemistry C ◽

10.1039/d0tc05816e ◽

2021 ◽

Vol 9 (9) ◽

pp. 3257-3263

Author(s):

Jianwei Liu ◽

Zhimin Ma ◽

Zewei Li ◽

Yan Liu ◽

Xiaohua Fu ◽

...

Keyword(s):

Room Temperature ◽

Single Component ◽

Color Tunable ◽

First Time ◽

Multi Mode

Two isomers pDCzPyCN and oDCzPyCN are designed and synthesized. Amazingly, oDCzPyCN manifest white afterglow at room temperature. This is the first time that single-component white afterglow has finally been realized.

Download Full-text

Single-crystalline epitaxial TiO film: A metal and superconductor, similar to Ti metal

Science Advances ◽

10.1126/sciadv.abd4248 ◽

2021 ◽

Vol 7 (2) ◽

pp. eabd4248

Author(s):

Fengmiao Li ◽

Yuting Zou ◽

Myung-Geun Han ◽

Kateryna Foyevtsova ◽

Hyungki Shin ◽

...

Keyword(s):

Transition Metal ◽

Density Functional ◽

Tight Binding ◽

Crystal Form ◽

Titanium Monoxide ◽

Binding Model ◽

Functional Theory ◽

Single Crystalline ◽

First Time ◽

Lattice Matched

Titanium monoxide (TiO), an important member of the rock salt 3d transition-metal monoxides, has not been studied in the stoichiometric single-crystal form. It has been challenging to prepare stoichiometric TiO due to the highly reactive Ti2+. We adapt a closely lattice-matched MgO(001) substrate and report the successful growth of single-crystalline TiO(001) film using molecular beam epitaxy. This enables a first-time study of stoichiometric TiO thin films, showing that TiO is metal but in proximity to Mott insulating state. We observe a transition to the superconducting phase below 0.5 K close to that of Ti metal. Density functional theory (DFT) and a DFT-based tight-binding model demonstrate the extreme importance of direct Ti–Ti bonding in TiO, suggesting that similar superconductivity exists in TiO and Ti metal. Our work introduces the new concept that TiO behaves more similar to its metal counterpart, distinguishing it from other 3d transition-metal monoxides.

Download Full-text

Methane to Methanol Conversion Facilitated by Anionic Transition Metal Centers: The Case of Fe, Ni, Pd, and Pt

The Journal of Physical Chemistry A ◽

10.1021/acs.jpca.0c10577 ◽

2021 ◽

Author(s):

Safaa Sader ◽

Evangelos Miliordos

Keyword(s):

Transition Metal ◽

Methanol Conversion ◽

Metal Centers

Download Full-text

Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽

10.3390/antibiotics10080893 ◽

2021 ◽

Vol 10 (8) ◽

pp. 893

Author(s):

Olufunto T. Fanoro ◽

Sundararajan Parani ◽

Rodney Maluleke ◽

Thabang C. Lebepe ◽

Jose R. Varghese ◽

...

Keyword(s):

Gold Nanoparticles ◽

Cell Viability ◽

Leaf Extract ◽

Room Temperature ◽

Klebsiella Oxytoca ◽

Cost Effective ◽

Average Diameter ◽

Antibacterial Activities ◽

Inhibition Concentration ◽

First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

Download Full-text

Free-standing electrochemically coated MoSx based 3D-printed nanocarbon electrode for solid-state supercapacitor application

Nanoscale ◽

10.1039/d0nr06479c ◽

2021 ◽

Author(s):

Kalyan Ghosh ◽

Martin Pumera

Keyword(s):

Solid State ◽

Transition Metal ◽

Electrochemical Deposition ◽

Room Temperature ◽

Free Standing ◽

Metal Chalcogenide ◽

Supercapacitor Application ◽

3D Printed

Room temperature electrochemical deposition of transition metal chalcogenide (MoSx) on 3D-printed nanocarbon fibers based electrodes for custom shaped solid-state supercapacitor.

Download Full-text