Table 3.

Nitrosyl and carbonyl IR stretching frequencies for species 6–12 (KBr pellet)

Compound	νCO (cm−1)	νNO (cm−1)
[Fe(DPPM)(NO)2(CO)], 6	2014, 1994, 2005a	1763, 1720 (s), 1700, 1761,a 1718a
[Fe2(μ-DPPM)(NO)4(CO)2], 7	2005, 2004a	1760, 1719 (s), 1702, 1764,a 1718a
[Fe2(μ-DPPA)(NO)4(CO)2], 8	2020, 2005	1767, 1716
[Fe2(μ-DPPH)(NO)4(CO)2], 9	1999	1755, 1701
[Fe2(μ-DPPB)(NO)4(CO)2], 10	2009, 1999	1760, 1707
[Fe2(μ-DPPM)2(NO)4], 11	–	1733, 1721, 1687, 1668
[Fe2(μ-DPPA)2(NO)4], 12	–	1723, 1679

^aMeasured in THF solution