I think you'll want another list(...):
AccountList= list(
list(AccountName= "Bob", AccountBalance= 5500.00),
list(AccountName= "Ann", AccountBalance= 9900.00)
)
The inner lists are for tupes, and the outer list is for the list of tuples.
From there, the natural next step is to make a table:
> AccountDF = dplyr::bind_rows(AccountList)
> AccountDF
# A tibble: 2 x 2
AccountName AccountBalance
<chr> <dbl>
1 Bob 5500
2 Ann 9900
I find this approach useful sometimes. I think you probably wouldn't run into it on DataCamp, StackOverflow or R4DS, though, so I wanted to mention it (since I think you were on the right track).