Study on the interaction between different solute molecules in a molecular beam produced by the spray-jet technique: an application to dendrimer/dye system

Improvement of the inlet system for the spray-jet technique for use in spectroscopic studies and molecular deposition

“…We previously developed a molecular beam apparatus with a spray-jet technique [1][2][3][4][5] that enables us to produce a molecular beam of neutral non-volatile molecules in vacuum from the sprayed mist of a sample solution. The apparatus is intended for use in spectroscopic studies or as a means of molecular deposition.…”

“…Fig. 1 shows the spray-jet inlet system which consists of an ultrasonic nebulizer (OMRON, NE-U17, 1.6 MHz), an inlet chamber, and a pulsed nozzle (Paker Hannifin, 9-279-900) as previously described [1][2][3][4][5]. In the ultrasonic nebulizer, the generation of a capillary wave on the solution surface leads to the production of a mist of solution, and the atomized droplet size therefore depends on the surface tension and the density of the solution [11].…”

“…For spectroscopic studies, we previously used the sprayjet molecular beam apparatus to analyze various sample solutions of non-volatile functional molecules, including a liquid crystal molecule, 4V -n-pentyl-4-cyanobiphenyl (5CB), a naphthalene derivative, 1,5-dihydroxy naphthalene, dye molecules such as 4-dicyanomethylene-2-methyl-6-p-dimethylaminostyryl-4H-pyran (DCM), Rhodamine B, and chloro[tri-tert -butyl-subphthalocyaninato]boron(III) (TBSubPc), and dendrimer molecules such as poly(propylene imine) dendrimers with different generations [1][2][3][4][5].…”

“…The inlet cap is made of aluminum with dimensions as described in Fig. 2, and it has approximate inner volume of 1320 mm 3 . The diameter of the exit pinhole of the inlet cap is 1 mm.…”

Deposition of Thermally Unstable Molecules with the Spray-Jet Technique on Au(111) Surface

“…A molecular beam of nonvolatile molecules was produced in the main chamber, while the solvent was reduced during passing through some chambers that were differentially pumped. Using a combination of this technique and multiphoton ionization time-of-flight mass spectroscopy (MPI-TOFMS), we have succeeded in obtaining a mass spectrum of single target molecules, such as dendrimers, dye molecules, and porphyrin derivatives. − We have applied the spray-jet technique to the deposition of a small molecule on a clean Au(111) surface; a subphthalocyanine derivative was successfully deposited on the surface and the molecular structure observed with UHV STM is comparable to that prepared by thermal evaporation , …”