The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. [a,b] Robert M. Edkins, [a,b] Laura J. Sewell, [a] Andrew Beeby, [a] Andrei S. Batsanov, [a] Katharina Fucke, [b,c]

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