As I mentioned in my comment: IQ is a measurement that is believed to correlate with certain aspects of 'intelligence'. Executive function is "an umbrella term for cognitive processes such as planning, working memory, attention, problem solving, verbal reasoning, inhibition, mental flexibility, multi-tasking, initiation and monitoring of actions." The two are not directly comparable.
However there are measures of executive function through tests like Wisconsin card sorting, verbal fluency, and trial making, cognitive estimates test, verbal fluency for animals, simplified six element (Burgess et al., 1998; Ardila, Pineda, & Rosselli, 2000). Burges et al. (1998) found that these load on 3 main factors: inhibition, intentionality, and executive memory. Ardila et al. (2000) found that these tests do not correlate well with IQ tests and concluded that traditional intelligence tests are not an appropriate metric for executive function.
However, Mahone et al. (2002) studied normal and ADHD children and found that some measures of executive function (Rey Osterrieth Complex Figure, Variables of Attention – Visual
Test, Letter Word Fluency) correlated moderately with IQ. In fact IQ scores accounted for a greater proportion of variance in the EF measures (~10% of the variance) than the diagnosis of ADHD (~0.4% of the variance). They also found that measures of executive function at average IQ differ between children with ADHD and those without. However, this effect disappears for children with above average IQ.
To me this discrepancy suggests that we don't know how to measure executive function very well. This is to be expected, since a huge umbrella term like executive function is a tell-tale sign that we are lumping a lot of things we don't understand well together under one umbrella until we learn more.
Ardila, A., Pineda, D., & Rosselli, M.  "Correlation Between Intelligence Test Scores and ExecutiveFunction Measures." Archives of Clinical Neuropsychology 15(1): 31-36.
Burgess, P.W., Alderman, N., Evans, J., Emslie, H., & Wilson, B.A.  "The ecological validity of tests of executive function." Journal of the International Neuropsychological Society 4: 547-558.
Mahone, E.M., Hagelthorn, K.M., Cutting, L.E., Schuerholz, L.J., Pelletier, S.F., Rawlins, C., Singer, H.S., & Denckla, M.B.  "Effects of IQ on Executive Function Measures in Children with ADHD." Child Neuropsychology 8(1): 52-65.