Architecture of framework copper(I) halide π-complexes with N-allyl-N,N,N′,N′-tetramethyl-ethylenediaminium and N,N′-diallyl-N,N,N′,N′-tetramethylethylenediaminium: Synthesis and crystal structure of [{C2H4N2(H+)×(CH3)4(C3H5)} Cu4Cl6] and [{C2H4N2(CH3)4(C3H5)2}0.5Cu2Cl1.67Br1.33] |