Accession Number:

ADA207767

Title:

Doubly Charged Cluster of 1.1-Difluoroethylene: Observation of an Anomalous Critical Size

Descriptive Note:

Technical rept. no. 4

Corporate Author:

STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY

Personal Author(s):

Report Date:

1989-01-01

Pagination or Media Count:

9.0

Abstract:

A field of growing interest is the observation of doubly charged molecular cluster ions Mn2 generated through electron impact ionization. Current work indicates that these cluster ions are composed of two separate cations generated via two sequential single ionization events of one incoming electron. These doubly charged cluster ions can then be detected through mass spectroscopy, if their size, n, is larger then n2, a critical value where the coulombic repulsion is offset by the cohesive forces of solvation. We present in this communication the first observation of a critical size n2 of 9 for doubly charged clusters of 1,1-difluoroethylene. This is a highly unusual result in that it is the lowest critical size measured so far the previous record was n2 21 for sulfur dioxide. In addition, this is the first example of a doubly charged cluster where its critical size is not predicted by the Echt scaling law that the critical size of the doubly charged cluster is proportional to the inverse of the product of Tc and V to the 13 power, where Tc is the critical temperature and v is the molecular volume. This suggests that the doubly charged CH2CF2 clusters are packed in a non-spherical arrangement ie, chains, rings, or stacking of the ethylene planes.

Subject Categories:

  • Organic Chemistry
  • Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE