Liam Neeson has gushed about the 'explosive chemistry' he shared with his late wife Natasha Richardson.

The film star -- whose actress wife of 15 years died following a skiing accident in Mont Tremblant, Que., in 2009 -- recalled the first time he set eyes on Richardson after they met on the set of 1981's 'Excalibur.'

Neeson compared their chemistry to iconic dance partners Fred Astaire and Ginger Rogers.

Talking to Anderson Cooper during a '60 Minutes' interview that aired on Sunday, Neeson said: "She was a radiant beauty. Yeah, cascading hair. I remember ... that was very, very attractive.

"I'd never had that kind of an explosive chemistry situation with an actor or actress.

"She and I were like Astaire and Rogers. We had just this wonderful kind of dance, free dance on stage every night, you know?"

The pair had two sons, Michael, 19, and Daniel, 18, together, and Neeson said he admired her "motherly instinct" and the way she looked after their family.

He added: "(Natasha) cared for everybody. She had a motherly instinct. And she'd make dinners for everyone and just looked after us all."

Neeson has been in an on-and-off-again relationship with PR executive Freya St. Johnston since 2010.