[skp524]

Is this phenomenon related to the intermolecular hydrogen bonding between DMSO and chloroform ? Can anyone give some suggestion to my point?

[cheese (MSW)]

F. A. Cotton, G. Wilkinson, C. A. Murillo, M. Bochmann, Advanced Inorganic Chemistry 6th ed (1999).
Unfortunately, both Cotton & Wilkinson have died and there will be no 7th ed of this famous text affectionately called “The Bible” by inorganic chemists.
Nevertheless, the 6th ed is a good place to start a lit search.  On page 54 you’ll find that C-H...O interactions although weak are indeed known (but I already knew about Cl3C-H...O (solv)  ).  On page 826 there is a discussion of Schiff-base cmplxs of Co(II) and their ability to pick up O2.  Let’s consider [Co(salen)(DMSO)]O2 in CHCl3:
Co(salen)   + DMSO  +  O2 ⇋  Co(salen)(DMSO)O2
In CHCl3 the equilibrium could indeed lay more to the left due to DMSO....HCCl3 interactions. Because it is a delicate balance it would not take a strong interaction to tip Keq to the left.
How to test? Co(salen)  and Co(salen)(DMSO)O2 will have different UV-vis spectra so can determine Keq.  (Make up standard soln of Co(salen) under N2.)
Change CHCl3 to CDCl3 (a common NMR solvent): DMSO....DCCl3 interaction expected to be stronger hence a further diminution in Keq; use CH2Cl2 as solvent: much less H-bonding if any at all, but other changes due to solvent effects expected to be small;  Keq predicted to increase significantly.