I am trying to create this dictionary using a List of type string (productIds) but it is erroring:

**The part that is erroring is p => p:**
*Cannot implicitly convert type 'string' to 'System.Collections.Generic.IEnumerable'*

It doesn't make sense to me since p => p makes it so I am passing a string into the first param and then a new list of product categories into the second param.

```
Dictionary<string, IEnumerable<string>> missingProducts =
    productIds.ToDictionary<string, IEnumerable<string>>(
        p => p, p => p 
        new List<string>(productCategories));

```

Here is a working example in VB.NET that I am trying to convert over:

```
Dim productCategories As IList(Of String) = (From pc In prodCategories Select pc.CategoryName).ToList()

Dim missingProducts As Dictionary(Of String, IList(Of String)) = productIds.ToDictionary(Of String, IList(Of String))(Function(p) p, Function(p) New List(Of String)(productCategories))

```