Table 2.

Carbonyl stretching frequencies (cm⁻¹) from the SEC measurements.

Complex	Solvent	Native State	1e Reduction State	2e Reduction State
1	MeCN	2026, 1933, 1922	1973, 1931, 1878, 1852	1909, 1811
	DMA	2021, 1930, 1912	1969, 1927, 1875, 1853	1907, 1810
2	MeCN	2021, 1915, 1897	1997, 1886, 1866	1986, 1850
	DMA	2016, 1912, 1890	1992, 1879, 1860	1981, 1860
3	MeCN	2026, 1932, 1921	1974, 1932, 1878, 1854	1917, 1816
	DMA	2021, 1930, 1912	1972, 1929, 1877, 1855	1916, 1815
4	MeCN	2014, 1903, 1883	1998, 1882, 1864	1986, 1862
	DMA	2009, 1899, 1877	not observed	1980, 1859