Ok Thanks 

ReB2 is still unexplored material. I am afraid that these data simply was not determined. Hence, empty places are in data sheet. 

There are several methods to estimate Thermal conductivity in liquid state. If you want, if they are useful for you, I can suggest them. 

Mariano.

If you have some data, you can try this 

http://www.mhtl.uwaterloo.ca/old/onlinetools/airprop/airprop.html

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

Enthalpy of formation for ReB2 can retrieved from:Article Standard enthalpies of formation of NbB2, MoB, and ReB2 by h...

Article Thermochemistry of Alloys of Transition Metals and Lanthanoi...

Article Enthalpies of Formation of Transition Metal Diborides: A Fir...

Heat capacity for ReB2 can be found at:Article Electronic and thermodynamic properties of ReB2 under high p...

The phase diagram for the Re-B system can be found at:Article Phase diagram of the system rhenium-boron

Article Binary Constitution Diagrams of Systems Composed of Various ...

Thermodynamic data for Re7B3 and Re3B was published at:Article Compressibility, microcalorimetry, elastic properties and EE...