Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
Nano Lett. 2009 Dec;9(12):4083-7. doi: 10.1021/nl902300y.
We report a facile, two-step synthetic method for preparing truly monodiserse Au(144)(SCH(2)CH(2)Ph)(60) nanoparticles with their formula determined by electrospray mass spectrometry in conjunction with other characterization. A remarkable advantage of our synthetic approach lies in that it solely produces Au(144)(SCH(2)CH(2)Ph)(60) nanoparticles, hence, eliminating nontrivial, postsynthetic steps of size separation, which has proven to be very difficult. This advantage makes the approach and the type of nanoparticles generated by it of broad utility for practical applications. Unlike their larger counterparts, Au nanocrystals (typically >2 nm) that are crystalline and show a prominent surface plasmon resonance band at approximately 520 nm (for spherical particles), the Au(144)(SCH(2)CH(2)Ph)(60) nanoparticles instead exhibit a stepwise, multiple-band absorption spectrum, indicating quantum confinement of electrons in the particle. In addition, these ultrasmall nanoparticles do not adopt face-centered cubic structure as in Au nanocrystals or bulk gold.
我们报告了一种简便的两步合成方法，可制备真正单分散的 Au(144)(SCH(2)CH(2)Ph)(60)纳米粒子，其分子式通过电喷雾质谱法结合其他表征方法确定。我们的合成方法的一个显著优点在于，它仅产生 Au(144)(SCH(2)CH(2)Ph)(60)纳米粒子，因此消除了尺寸分离的非平凡后合成步骤，这已被证明非常困难。该优势使得该方法及其所产生的纳米粒子类型具有广泛的实际应用用途。与较大的同类物相比，Au 纳米晶体（通常 >2nm）是结晶的，在大约 520nm 处显示出明显的表面等离子体共振带（对于球形粒子），而 Au(144)(SCH(2)CH(2)Ph)(60)纳米粒子则表现出逐步的、多波段吸收光谱，表明电子在粒子中的量子限制。此外，这些超小纳米粒子不采用 Au 纳米晶体或体金中的面心立方结构。
