From the Angry Robot site:
"We are absolutely thrilled to be able to announce the launch of our new YA imprint, Strange Chemistry The imprint will launch in September 2012, with five titles appearing before the end of that year, before settling down to one book each month. Strange Chemistry will follow AR’s strategy of co-publishing its books simultaneously in the US and UK, in both eBook and paperback formats. Subject matter will include fantasy, science fiction, supernatural and horror, and as with Angry Robot the lines between those genres are likely to be very blurry at times."
You can find an interview with editor Amanda Rutter on YAtopia. According to the interview, Strange Chemistry will be open only to agented submissions.