We have synthesized two copper nanoclusters(NCs)with a protection of the same ligand diphenylphosphino-2-pyridine(C_(17)H_(14)NP,dppy for short),formulated as Cu_(4)(dppy)_(4)Cl_(2)and Cu21(dppy)10,respectively.The fo...We have synthesized two copper nanoclusters(NCs)with a protection of the same ligand diphenylphosphino-2-pyridine(C_(17)H_(14)NP,dppy for short),formulated as Cu_(4)(dppy)_(4)Cl_(2)and Cu21(dppy)10,respectively.The former one bears a distorted tetrahedron Cu4 core with its six edges fully protected by chlorine and dppy ligands,while the latter presents a symmetric Cu_(21)core on which ten dppy molecules function as monolayer protection via well-organized monodentate or bidentate coordination.Interestingly,the Cu_(4)(dppy)_(4)Cl_(2)cluster exhibits a strong yellow emission at∼577 nm,while Cu_(21)(dppy)_(10)displays dual emissions in purple(∼368 nm)and green(∼516 nm)regions respectively.In combination with TD-DFT calculations,we demonstrate the origin of altered emissions and unique stability of the two copper nanoclusters pertaining to the ligand coordination and metallic superatomic states.展开更多
Hydroge nation of p-n itrophe nol(PNP)towards the con versi on to p-ami nophe no I(PAP)by metal catalysis is known as a simple and I eco-frie ndly tech nique for the production of corresp on ding in dustrial and pharm...Hydroge nation of p-n itrophe nol(PNP)towards the con versi on to p-ami nophe no I(PAP)by metal catalysis is known as a simple and I eco-frie ndly tech nique for the production of corresp on ding in dustrial and pharmaceutical in termediates.While continu ous efforts are paid for§more sustainable and greener procedures by using transition metal catalysts,atomic-precise reaction mechanism for the PNP-to-PAP is still illusive to be fully un derstood.Utilizi ng a dry-wet com bined strategy,here we have syn thesized water-soluble Pd8 nano clusters(NCs)with mercaptosuccinic acid(H2SMA)as the ligand,and the Pd8 NCs found high catalytic performance for the conversion of PNP-to-PAP,as identified by the electrospray ionization mass spectrometer(ESI-MS)measurement.The gradual changes over time of ultraviolet-visible(UV-vis)spectra of PNP really display the catalytic reduction by NaBH4 in presence of Pd8 NCs.Further,in-depth charge transfer interactions between PNP and the Pd8 clusters at the proton-rich conditions are investigated by natural bond orbital(NBO)analysis and electron density differenee(EDD)analysis.The exothermic and kinetic-favorable reaction pathways are addressed,based on successive PNP hydrogenation and H2O removal processes,clarifying the reaction mechanism of Pd catalysts.It is worth noting that this solid-state synthetic route for such Pd8 clusters enables gram-scale quantity of production in likely practical use.展开更多
基金the National Natural Science Foundation of China(Nos.22003072 and 21722308),the Ministry of Science and Technology of the People’s Republic of China(No. 2020YFA0714602).
文摘We have synthesized two copper nanoclusters(NCs)with a protection of the same ligand diphenylphosphino-2-pyridine(C_(17)H_(14)NP,dppy for short),formulated as Cu_(4)(dppy)_(4)Cl_(2)and Cu21(dppy)10,respectively.The former one bears a distorted tetrahedron Cu4 core with its six edges fully protected by chlorine and dppy ligands,while the latter presents a symmetric Cu_(21)core on which ten dppy molecules function as monolayer protection via well-organized monodentate or bidentate coordination.Interestingly,the Cu_(4)(dppy)_(4)Cl_(2)cluster exhibits a strong yellow emission at∼577 nm,while Cu_(21)(dppy)_(10)displays dual emissions in purple(∼368 nm)and green(∼516 nm)regions respectively.In combination with TD-DFT calculations,we demonstrate the origin of altered emissions and unique stability of the two copper nanoclusters pertaining to the ligand coordination and metallic superatomic states.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21722308 and 21802146)Beijing Natural Science Foundation(No.2192064)+2 种基金CAS Key Research Project of Frontier Science(No.QYZDB-SSWSLH024)Frontier Cross Project of National Laboratory for Molecular Sciences(No.051Z011BZ3)Z.X.L.acknowledges the National Thousand Youth Talents Program.
文摘Hydroge nation of p-n itrophe nol(PNP)towards the con versi on to p-ami nophe no I(PAP)by metal catalysis is known as a simple and I eco-frie ndly tech nique for the production of corresp on ding in dustrial and pharmaceutical in termediates.While continu ous efforts are paid for§more sustainable and greener procedures by using transition metal catalysts,atomic-precise reaction mechanism for the PNP-to-PAP is still illusive to be fully un derstood.Utilizi ng a dry-wet com bined strategy,here we have syn thesized water-soluble Pd8 nano clusters(NCs)with mercaptosuccinic acid(H2SMA)as the ligand,and the Pd8 NCs found high catalytic performance for the conversion of PNP-to-PAP,as identified by the electrospray ionization mass spectrometer(ESI-MS)measurement.The gradual changes over time of ultraviolet-visible(UV-vis)spectra of PNP really display the catalytic reduction by NaBH4 in presence of Pd8 NCs.Further,in-depth charge transfer interactions between PNP and the Pd8 clusters at the proton-rich conditions are investigated by natural bond orbital(NBO)analysis and electron density differenee(EDD)analysis.The exothermic and kinetic-favorable reaction pathways are addressed,based on successive PNP hydrogenation and H2O removal processes,clarifying the reaction mechanism of Pd catalysts.It is worth noting that this solid-state synthetic route for such Pd8 clusters enables gram-scale quantity of production in likely practical use.