Hello i did a lab where i made up Cu(NH
3)SO
4 H
2O and obtained a IR spectrum


Sorry about the bad images. I know that SO
4 (v
3) is around 1104/cm and NH
3 (δd) is around 1628/cm but i have no idea what that big dip in at 3201/cm is. I have to figure out if this is a Sulfato ligand binding as unidentate complex, bidenate complex, or bridged bidentate complex. I have watch a bunch of youtube videos and lab reports and cant understand how to properly read this. I read my text book as well but still dont get it. I was also a bit confused because i thought the NH
3 would be double bonded to the SO
4 since its in the double bond range but thats not an option. Please help me out if you can and directed me somewhere else if you cant. Thanks.