Interplay of the CuCu distance and coordination geometry as a factor affecting the quantum efficiency in dimeric copper(i) halide complexes with derivatives of 4 pyrazolylpyrimidine 2 thiol Dalton Transactions (RSC Publishing) Theoretical study of copper binding to GHK peptide ScienceDirect GHK Cu 50mg Copper Tripeptide Research Compound 99% GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link