Indium dicarbonyl: Matrix isolation ESR and IR study

Indium atoms and CO molecules were co-condensed in argon matrices at ∼4 K. Examination of the resulting matrices by IR and ESR revealed the formation of the In(0) dicarbonyl complex. No evidence was obtained for the formation of In(0) monocarbonyl. The characteristic symmetric and antisymmetric stretching modes of the dicarbonyl system were observed at 2037 and 1997 cm-1, respectively. The g tensor and the 115In hyperfine and quadrupole coupling tensors of the complex were determined as follows: gz = 1.978, gx = 1.980, gy = 1.969; Az = +420, Ax = -400, Ay = -440 MHz; and Pz = +7.2, Px = Py = -3.6 MHz. The x and y axes lie within the molecular plane of the complex having a bent, planar structure. The unpaired electron density is essentially all in the In pπ orbital perpendicular to the plane. © 1989 American Chemical Society.