Create a folder in SPList and then add a list item . NOT FOR DOC LIBRARY c#

Am having probs in putting a new item in a new folder i created using the

splist.items.add( web.url + '/list1' ,
spFileSystemObjectType.Folder ,
'folder1' )

so with folder 1 created i just want an splistitem added to the folder created.

I cant get it to work

Thanks kindly for this.