THE ACFT COLLIDED WITH THE TERRAIN DURING THE PLTS ATTEMPT TO COMPLETE A NIGHT X-COUNTRY IN IMC WX CONDITIONS. THE FLT HAD PROGRESSED APRX 4 HRS & 34 MIN FROM SC TO NY PRIOR TO THE CRASH. THE PLT WAS NOT CURRENTLY RATED TO FLY IFR. THE PLT REPORTED BY RADIO TO SYRACUSE APPRCH CONTROL THAT HE LOST AN ENG TRYING TO APPROACH HIS DEST AND HE WAS GOING TO BINGHAMTON NY. THE WX WENT BELOW MINIMUMS AT BINGHAMTON AND THE CONTROLLING AGENCIES WERE UNABLE TO MAINTAIN RADIO CONTACT WITH N2680S. CONTACT WAS TRIED THRU OTHER ACFT . ONE ACFT SAID HE HEARD TRANSMISSIONS FROM N2680S BUT NO ANSWERING ACKNOWLEDGEMENTS. A SHORT TIME LATER RADAR CONTACT WAS LOST. THE ACFT CRASHED IN A FIELD WITH A TREE LINE NEAR LAPEER NY. ON SITE INVESTIGATION DETERMINED THAT BOTH ENGINES WERE PRODUCING PWR AT IMPACT. ALL CHECKS INDICATED NORMAL OPERATION. THERE WAS NO EVIDENCE OF ANY MALFUNTION OF THE ACFT. TOXICOLOGY SCREENING RESULTS WERE NEGATIVE FOR THE PLT.