Can a Procedure for the Growth of Single-layer Graphene on Copper be used in Different Chemical Vapor Deposition Reactors?

In the last decade, catalytic chemical vapor deposition (CVD) has been intensively explored for the growth of single-layer graphene (SLG). Despite the scattering of guidelines and procedures, variables such as the surface texture/chemistry of catalyst metal foils, carbon feedstock, and growth process parameters have been well-scrutinized. Still, questions remain on how best to standardize the growth procedure. The possible correlation of procedures between different CVD setups is an example. Here, two thermal CVD reactors were explored to grow graphene on Cu foil. The design of these setups was entirely distinct, one being a “showerhead” cold-wall type, whereas the other represented the popular “tubular” hot-wall type. Upon standardizing the Cu foil surface, it was possible to develop a procedure for cm²-scale SLG growth that differed only by the carrier gas flow rate used in the two reactors.     

A weight-function approach for determining watershed initial conditions for combustion waves

In many generic combustion models, one finds that a combustionwave will develop with a specific wave speed. However, thereare possible initial temperature profiles which do not evolveinto such waves, but rather die out to the ambient temperature.There can exist, in some models, a clear distinction betweenthose initial conditions that do evolve into combustion wavesand those that do not; this is sometimes referred to as thewatershed initial condition. When fuel consumption is consideredto be negligible, analytical methods can be used to obtain theexact watershed. In this paper, we consider the problem of determiningpseudo-watersheds and ascertaining the relationship betweenthese pseudo-watersheds and the exact watersheds. In the processa novel weight-function approach for infinite spatial domainsis developed.     

Preparation and Characterization of Antimony and Arsenic Tricyanide and Their 2,2′‐Bipyridine Adducts

The arsenic(III) and antimony(III) cyanides M(CN)₃ (M=As, Sb) have been prepared in quantitative yields from the corresponding trifluorides through fluoride–cyanide exchange with Me₃SiCN in acetonitrile. When the reaction was carried out in the presence of one equivalent of 2,2′‐bipyridine, the adducts [M(CN)₃ ? (2,2′‐bipy)] were obtained. The crystal structures of As(CN)₃, [As(CN)₃ ? (2,2′‐bipy)] and [Sb(CN)₃ ? (2,2′‐bipy)] were determined and are surprisingly different. As(CN)₃ possesses a polymeric three‐dimensional structure, [As(CN)₃ ? (2,2′‐bipy)] exhibits a two‐dimensional sheet structure, and [Sb(CN)₃ ? (2,2′‐bipy)] has a chain structure, and none of the structures resembles those found for the corresponding arsenic and antimony triazides.     

Bismuth Chloride–Sodium Nitrite: A Novel Reagent for Chemoselective N-Nitrosation

Bismuth(III) chloride–sodium nitrite was used as a mild and efficient reagent for N-nitrosation of various tetrazoles, secondary amines, and amides under ambient conditions. Nitrosation took place chemoselectively at the nitrogen atom, giving corresponding N-nitroso derivatives in good to excellent yield.     

Synthesis and Antimicrobial Activity Evaluation of Novel Oxadiazino/Thiadiazino‐Indole and Oxadiazole/Thiadiazole Derivatives of 2‐Oxo‐2H‐benzopyran

A series of novel oxadiazino/thiadiazino‐indole and oxadiazole/thiadiazole derivatives of 2‐oxo‐2H‐benzopyran were synthesized and evaluated for their antimicrobial activities against the bacteria Staphylococcus aureus, Salmonella typhi, and Escherichia coli and two fungal species Candida albicans and Aspergillus niger. The antibacterial activities were expressed as minimum inhibitory concentration (MIC₅₀) in microgram per milliliter. The title compounds 4b and 10b revealed promising antibacterial activity whereas 6d , 7d , 9d , and 10b exhibited significantly impressive antifungal activity.