Borah Bibek Jyoti, Borah Subrat Jyoti, Dutta Dipak Kumar
Materials Science Division, CSIR-North East Institute of Science and Technology, Jorhat 785 006, Assam, India.
J Nanosci Nanotechnol. 2013 Jul;13(7):5080-7. doi: 10.1166/jnn.2013.7576.
Multifunctional phosphine based ligands, 1,1,1-tris(diphenylphosphinomethyl)ethane [CH3C(CH2 PPh2)3][P3] and 1,1,1-tris(diphenylphosphinomethyl)ethane trisulphide [CH3C(CH2P(S)Ph2)3][P3S3] have been introduced to stabilize Au(o)-nanoparticles having small core diameter and narrow size distribution. The Au(o)-nanoparticles were synthesized by the reduction of HAuCl4 precursor with NaBH4 in the presence of ligand P3 or P3S3 using two phases, one pot reaction at room temperature. The Au(o)-nanoparticles exhibit face centered cubic (fcc) lattice having different crystalline shape i.e., single crystallite stabilized by P3 while P3S3 forms decahedral shapes. Surface plasmon bands at -520 nm and TEM study indicate particle size below 2 and 4 nm for Au(o)-nanoparticles stabilized by P3 and P3S3 respectively, which are attributable to the stronger interaction of Au(o) (Soft) with P (Soft) than Au(o) (Soft) with S (less Softer than P). Au(o)-nanoparticles stabilized by P3S3 shows higher thermal stability than that of P3. The synthesized Au(o)-nanoparticles serve as an efficient catalyst for one-pot, three-component (A3) coupling of an aldehyde, an amine and an alkyne via C-H alkyne-activation to synthesize propargylamines (85-96%) without any additives and precaution to exclude air.
基于多功能膦的配体，1,1,1-三（二苯基膦甲基）乙烷[CH3C(CH2PPh2)3][P3]和1,1,1-三（二苯基膦甲基）乙烷三硫化物[CH3C(CH2P(S)Ph2)3][P3S3]已被引入用于稳定具有小核直径和窄尺寸分布的Au(0)-纳米颗粒。Au(0)-纳米颗粒是在配体P3或P3S3存在下，通过用NaBH4还原HAuCl4前驱体，在室温下采用两相一锅法合成的。Au(0)-纳米颗粒呈现面心立方（fcc）晶格，具有不同的晶体形状，即由P3稳定的单晶粒，而P3S3形成十面体形状。在-520nm处的表面等离子体带和TEM研究表明，由P3和P3S3稳定的Au(0)-纳米颗粒的粒径分别低于2nm和4nm，这归因于Au(0)（软）与P（软）的相互作用比Au(0)（软）与S（比P软度小）的相互作用更强。由P3S3稳定的Au(0)-纳米颗粒显示出比P3更高的热稳定性。合成的Au(0)-纳米颗粒可作为一种高效催化剂，用于通过C-H炔烃活化进行醛、胺和炔烃的一锅三组分（A3）偶联反应，以合成炔丙胺（85-96%），无需任何添加剂且无需采取排除空气的预防措施。
