We have identified new organosilicon coolants for direct immersion phase change cooling of electronic systems using a computer-aided molecular design (CAMD) approach combined with a figure of merit (FOM) analysis (hereafter termed the CAMD-FOM approach). Seven candidates with predicted thermophysical properties in the range suitable for direct immersion cooling of electronics were identified, and the thermophysical properties of two candidates, dimethoxydimethylsilane and ethyldimethylsilane, were measured in order to validate the CAM.D-FOM procedure. In addition, the pool boiling characteristics of a mixture of dimethoxydimethylsilane and HFE 7200 (10:90 w/w) on a grooved silicon surface were investigated and compared with those of pure HFE 7200. The addition of dimethoxydimethylsilane was shown to lead to an approximately 20% enhancement in the critical heat flux, confirming that the CAMD-FOM approach can be employed for designing new heat transfer fluids.