[Tucker_16]

whyare melting points of Sublimes so much higher than just the regular compund?

[Dan]

Your question makes no sense. Re-write it and someone may be able to help you. Give a specific example too, that should make things clearer.

[Tucker_16]

the melting point of the sublime of SnI4 is like 700 degrees celcius but the melting point of SnI4 is only like 145

[Arkcon]

Some substances (compound or element) melt, when heated, and vaporize when heated further.  Some substances don't melt, but simply vaporize, for example elemental iodine, this is called sublimation. 

You can get the sublimation for substances that usually melt, by reducing the pressure.  This is the case with ice, which can "disappear" on days when the temperature is below freezing.  You can melt something that usually sublimes, if you increase the pressure, this is done with CO₂ for use in supercritical extraction.  As the pressure over a liquid varies, the temperature for its vaporization changes.  Therefore, while it's technically correct to find multiple values for melting, sublimation and vaporization, you're not correct in using the word "sublimes" as a noun, nor connecting the "sublime" with the phenomena.

The nature of Sn(IV) Iodide is confusing for me, Wikipedia says it melts at 143 C, a google search leads me to a text by Wiley publishers that says it sublimes at 180 C, but I don't have the context for these observations.  They can't both be right as is, but neither source specifies pressure, so, they might be, I just can't tell.

[AWK]

Meltin point od SnCl4 is -32.9 C, boiling point is 114,1 (according to Knovel)
 for SnI4   143 and  364 respectively.

[Arkcon]

Meltin point od SnCl4 is -32.9 C, boiling point is 114,1 (according to Knovel)
 for SnI4   143 and  364 respectively.

And the 108 C sublimation temp, is under some sort of vacuum, I guess, but wouldn't it melt first?  Meh.  Bad example of sublimation.  Damn, but this Google book search is annoying sometimes.  You think you've found the tiny tidbit of info you want, then you go to a page, with a scanned book page, that doesn't even have your factoid, but has an Amazon link.

[Borek]

melts at 143 C, a google search leads me to a text by Wiley publishers that says it sublimes at 180 C

Same numbers listed in my handbook, no idea how to read them.

[AWK]

May be the melting point is at higher pressure (as for iodine, for example).

But as a student I also met a problem in practical organic chemistry under subject - sublimation of naphtalene. When I tried them it became a problem of vapor condensation, but the vapors were obtained evidently from a melted naphtalene.

[Tucker_16]

im so sorry, i was looking at the question completly wrong it was SnF4 sublimes at 700 degrees celcius sorry for the confusion