Pyrimidine and Pyrazine as N‐Donor Ligands in Mercurous Complexes: [Hg 2 (Pym)](NO 3 ) 2 , [Hg 2 (Pym)](ClO 4 ) 2 , and [Hg 2 (Pyp) 2 ](ClO 4 ) 2

Colourless single crystals of [Hg 2 (Pym)](NO 3 ) 2 , [Hg 2 (Pym)](ClO 4 ) 2 und [Hg 2 (Pyp) 2 ](ClO 4 ) 2 were obtained from aqueous solutions of the respective components Hg 2 (NO 3 ) 2 ·2H 2 O, Hg 2 (ClO 4 ) 2 ·6H 2 O, pyrimidine (Pym) and pyrazine (Pyp). The crystal structures were determined from single‐crystal X‐ray diffractometer data. [Hg 2 (Pym)](NO 3 ) 2 : monoclinic, C2/c, Z = 8, a = 1607.4(2), b = 652.79(7), c = 2000.5(2) pm, β = 103.42(2)°, R all = 0.0530; [Hg 2 (Pym)](ClO 4 ) 2 : orthorhombic, Pnma, Z = 4, a = 1182.7(2), b = 1662.5(2), c = 607.9(1) pm, R all = 0.0438; [Hg 2 (Pyp) 2 ](ClO 4 ) 2 : orthorhombic, Aba2, Z = 4, a = 1529.39(9), b = 1047.10(14), c = 1133.49(15) pm, R all = 0.0381. The crystal structures of [Hg 2 (Pym)](NO 3 ) 2 and [Hg 2 (Pym)](ClO 4 ) 2 contain polymeric cationic chains [Hg 2 (Pym)] + that are arranged to corrugated layers between which the anions are situated. [Hg 2 (Pyp) 2 ](ClO 4 ) 2 consists of polymeric cationic layers that are built from (Hg 2 ) 2 (Hg 2 ) 2/2 (Pyp) 4 rings connected to each other; the perchlorate tetrahedra are located between these layers.