Synthesis, characterization and electrochemical recognition of metal ions of three new ferrocenyl derivatives containing pyridyl moiety

Three new ferrocene （Fc） based receptors with pyridyl moiety, named methyl-6- ferrocenoylacetyl-2-pyridine carboxylate （FcLl）, 1,1＇-（2,6-bispyridyl）bis-3-ferrocenyl-l,3-propanedione （FcL2）, ferrocenecarboxaldehyde-2,6-dipicolinoyhydrazone （FcL3） were synthesized, and further characterized by elemental analysis, IR spectra, UV-Vis spectra, 1H and 13C NMR. The electrochemical properties and ion sensing properties of FcL1, FcL2 and FcL3 were also investigated by means of cyclic voltammetry in ethanol solution with 0.1 mol/L LiC104 as the supporting electrolyte. The E~ values of the receptors increase with the scanning rate increasing at high scanning rate, and Ipa/Ipo approaches unity, indicating that the redox reaction is basically reversible. Their recognition performances to different metal cations such as Cd（II）, Co（II）, Cu（II）, Hg（II）, Mn（II）, Ni（II）, Zn（II） show that the FcL1 is responsive to Cu（II） with the maximum electrochemical shift of the FcL1 for Cu（II）of about 72.0 mV, whereas the FcL2 is responsive to Cu（II） and Mn（II） with shift of 102 mV and 109 mV, respectively, and the FcL3 is responsive to Hg（II） and Mn（II） with the shift of 53.0 mV and 54.0 mV, respectively. All the results show that these receptors may have potential applications in electrochemical sensor technology, material science, and molecular devices.

Photocatalytic conversion of CO to fuels with water by B-doped graphene/g-CN heterostructure

Photocatalytic reduction of carbon monoxide(CO)is a promising route to the production of high-value chemicals and fuels,as a supplement to high energy-input Fischer-Tropsch synthesis(FTS)and a key step in direct photo/electro-reduction CO_(2) to multi-carbon products.However,many current research efforts for high-efficiency FTS/CO_(2) reduction mainly focus on the metal-based catalysts,while metal-free and solar-driven photocatalysts are rarely explored.Here,by means of Lewis acid sites,a metal-free composite photocatalyst for CO reduction,namely boron(B)doped-graphene/g-C_(3)N_(4) heterostructure,is proposed.First-principles calculations show that the dopants(B)as catalytic sites can effectively capture and activate CO molecules and reduce CO to CH_(3)OH and CH_(4) in different doping content.It is worth noting that C_(2) products,i.e.,C_(2)H_(5)OH,can be produced with low free energy barriers on paradoped graphene/g-C_(3)N_(4).Meanwhile,the competitive hydrogen evolution reaction(HER)can be greatly suppressed,leading to the high selectivity of CO reduction.Moreover,the formation of a built-in electric field in heterostructure enhances the separation of photogenerated electrons and holes,which further accelerates the transmission of photogenerated electrons to the catalytic sites and improves the reaction efficiency.Overall,this work not only proposes a new strategy from a new perspective to solve problems of high energy consumption and low selectivity of FTS,but also provides a tandem strategy to solve problems of CO_(2) to multi-carbon products.

Regioselective synthesis of α-bromo-α,β-unsaturated carbonyl compounds via photocatalytic α-bromination reactions

A visible light-mediated approach for the preparation of α-bromo-α,β-unsaturated ketones and aldehydes was developed. In comparison to traditional methods that generally take two steps to afford the above compounds, this protocol was highlighted by its operational simplicity, avoiding using hazardous bromine and mild reaction conditions.

Redox-triggered hydroarylation of o-(hydroxyalkyl)arylalkynes with arylsulfonyl chlorides using visible light catalysis

A new radical-mediated method for the synthesis of 1-(2-(1,2-diarylvinyl)phenyl)ethan-1-ones by the redox hydroarylation of o-(hydroxyalkyl)arylalkynes with arylsulfonyl chlorides is described. This visible light catalysis method proceeds via a sequence of the radical addition of aryl group across the C?C triple bond, protonation and redox reaction, and represents a new redox transformation reaction directed by a neighboring hydroxyl group.

Synthesis of aziridines by visible-light induced decarboxylative cyclization of N-aryl glycines and diazo compounds

A visible-light induced decarboxylative aza-Darzens reaction between N-aryl glycines and diazo compounds was developed, which affords various mono-substituted aziridines in good yields.