Source for thermodynamic and/or transport properties
I have a CHEMKIN files with HCL:

HCL                1   344.7       3.339     0.000     0.000     1.000  !(singh)


344.7 should be $\varepsilon/k$ in K and 3.339 should be $\sigma$ in Angstroms.

! Species: HCL              CAS Number: 7647-01-0
! Name:    Hydrogen Chloride
! Source:  SNLL fit to 1986 JANAF tables, 4/21/89
! H0(298K) =      -22.0600 (Kcal/mole),  S0(298K) =       44.6500 (cal/mole-K)
HCL                42189CL  1H   1          G   300.000  5000.000 1000.00      1
 2.75533500e+00 1.47358100e-03-4.97125400e-07 8.10865800e-11-5.07206300e-15    2
-1.19180600e+04 6.51511600e+00 3.33853400e+00 1.26820700e-03-3.66691700e-06    3
 4.70399200e-09-1.83601100e-12-1.21315100e+04 3.19355500e+00                   4


Also, Poling [1] has some data on HCl, Cl$_2$, ClNO. You could estimate the other properties using group contributions to define critical properties and then corresponding state principle methods (like Chung's [2]) to get your temperature/pressure dependencies. You can then make your own curvefit for your conditions of interest. Not as good as curvefits from experimental data but it should get you in the ballpark...

[1] B. E. Poling, J. M. Prausnitz, and J. P. O’Connell. The Properties of Gases and Liquids, Fifth Edition. McGraw-Hill, 2001.

[2] T. H. Chung, M. Ajlan, L. L. Lee, and K. E. Starling. Generalized multiparameter corresponding state correlation for polyatomic, polar fluid transport properties. 27:671–679, 1988.