[Iron Man]

Hi,
In the context of the synthesis of a coordination compound were added 1 mmol of copper (I) bromide with 1 mmol of 2,5-dimethylpyrazine and were stirred in acetonitrile. Here, a solid precipitated from X, which was filtered off and dried.
An elemental analysis gave the following values​​: C: 28.65%, N: 11.12%, H: 3.21%. The content of
Copper and bromine additionally by atomic absorption spectroscopy (AAS) was determined: (Cu: 25.25%, Br: 31.75%).

As ratio formula I've got CuBrC6H8N2.

But what's the molecul formula???

Can somebody help me??

[sjb]

Hi,
In the context of the synthesis of a coordination compound were added 1 mmol of copper (I) bromide with 1 mmol of 2,5-dimethylpyrazine and were stirred in acetonitrile. Here, a solid precipitated from X, which was filtered off and dried.
An elemental analysis gave the following values​​: C: 28.65%, N: 11.12%, H: 3.21%. The content of
Copper and bromine additionally by atomic absorption spectroscopy (AAS) was determined: (Cu: 25.25%, Br: 31.75%).

As ratio formula I've got CuBrC₆H₈N₂.

But what's the molecul formula???

Can somebody help me??

Without some other analysis tool I'm not sure you can tell, but perhaps consider the stability of the Cu(I) ion.

[MOTOBALL]

I would run a MALDI-MS to determine MW on your analyte. Consult your friendly neighborhood mass spectrometrist for options.

If this does not work, or you don't have access to MS, one non-instrumental method is the depression of m.p. of a solid.  Look up Rast's method; essentially you have to be able to generate a homogeneous solution of your analyte in a warmed solid (typically camphor was used) for this to be viable.