II Halide-Pyridine Complexes

When the green iodide product is recrystallized (as above) from an ethanol-dimethylformamide mixture, brown crystals are obtained. These crystals, which analyze for Crl2-4py, are filtered off and dried under vacuum. Anal. Calcd. for Crl2-4py Cr, 8.4 I, 40.8 C, 38.6 H, 3.2. Found Cr, 8.3 I, 40.6 C, 38.6 H, 3.2. 

The complexes CrBr2-2py and Crl2-4py react further with pyridine to give dark green products which are recrystallized (as above) from an ethanol-pyridine mixture. The compound CrCl2-2py does not react further with pyridine. Anal. Calcd. for CrBr2 6py Cr, 7.6 Br, 23.3 C, 52.6 H, 4.4. Found Cr, 7.6 Br, 23.5 C, 52.3 H, 4.5. Anal. Calcd. for Crl2-6py Cr, 6.7 I, 32.5 C, 46.2 H, 3.9. Found Cr, 6.1 I, 31.7 C, 46.2 H, 3.9. 

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