Cyano complexes of transition metal ions such as F

正确答案：CN is a strong-field ligandwhich causes a greater energy separation of the two group of d electrons than H₂O does．Promotion of an electron from a lower to a higher d level can result from the absorption of the appropriate component of white lightso the transmitted light is colored．For the energy difference produced by H₂O is smaller than that by cyanothe color we observed changes from yellow tO green or blue．
CNisastrong-fieldligand,whichcausesagreaterenergyseparationofthetwogroupofdelectronsthanH2Odoes．Promotionofanelectronfromalowertoahigherdlevelcanresultfromtheabsorptionoftheappropriatecomponentofwhitelight,sothetransmittedlightiscolored．FortheenergydifferenceproducedbyH2Oissmallerthanthatbycyano,thecolorweobservedchangesfromyellowtOgreenorblue．