Let's assume your list of lists is called 'a':
data <- data.frame(matrix(unlist(a), nrow=145, byrow=T))
The above command will convert all character columns to factors. But, to avoid this add the stringsAsFactors parameters to this call.
data <- data.frame(matrix(unlist(a), nrow=145, byrow=T),stringsAsFactors=FALSE)
NOTE: You need to be careful here if all your data is not of same type.
When you pass the data through a matrix, all your data is coerced into a common type.
For Example: If you have one column of character data and one column of numeric data then the numeric data will be coerced to string by matrix() and both to factor by data.frame()