Non-centrosymmetric one-to three-dimensional CuSCN-based coordination polymers with substituted pyrazine or pyrimidine spacer ligands can be prepared by self-assembly in acetonitrile solution at 100°C. Both 1 I [CuSCN(2 NCpyz) 2 ] (1) (2 NCpyz = 2-cyanopyrazine) and 1 I [CuSCN(4 HOpym) 2 ] (3) (4 HOpym = 4-hydroxypyrimidine) contain single zigzag CuSCN chains as their central backbone and crystallise in polar space groups (monoclinic Cm and orthorhombic Ama2). In 2 I [(CuSCN) 2 (l-2 Mepyz)] (2) (2 Mepyz = 2-methylpyrazine), 1 I [(CuSCN) 2 ] staircase double chains are connected by bridging 2 Mepyz ligands to afford a lamellar polymer (triclinic P 1). Whereas 2 I [CuSCN(5 Brpym)] (4) (5 Brpym = 5-bromopyrimidine) with its honeycomb 2 I [CuSCN] layers is chiral (monoclinic P2 1 ), both 3 D polymers 3 I [(CuSCN) 2 (l-pym)] (5) and 3 I [(CuSCN) 3 (l-4 Mepym)] (6) (4 Mepym = 4-methylpyrimidine) contain polar coordination networks (orthorhombic Fdd2 and monoclinic Pc). The CuSCN framework in (5) consists of thiocyanate bridged 1 I [CuS] chains, that in 6 of interlocked 2 I [CuSCN] and 2 I [Cu 2 S(SCN)] sheets. Nichtzentrosymmetrische Koordinationspolymere mit CuSCN und substituierten Pyrazin-und Pyrimidinliganden Inhaltsu È bersicht. Nichtzentrosymmetrische ein-bis drei-dimensionale Koordinationspolymere mit CuSCN und substituierten Pyrazin-oder Pyrimidinliganden ko È nnen durch Selbstorganisation in Acetonitrillo È sung bei 100°C dargestellt werden. Sowohl 1 I [CuSCN(2NCpyz)] (1) (2 NCpyz = 2-Cyanopyrazin) als auch 1 I [CuSCN(4 HOpym) 2 ] (3) (4 HOpym = 4-Hydroxypyrimidin) enthalten einfache zickzackartige CuSCN-Ketten als zentrales Ru È ckgrat und kristallisieren in polaren Raumgruppen (monoklin Cm bzw. orthorhombisch Ama2). In 2 I [(CuSCN) 2 (l-2 Mepyz)] (2) (2 Mepyz = 2-Methylpyrazin), erzeugt die Verknu È pfung von treppenartigen Doppelketten 1 I [(CuSCN) 2 ] durch 2 Mepyz-Bru È ckenliganden ein schichtartiges Polymer (triklin P 1). Wa È hrend 2 I [CuSCN(5 Brpym)] (4) (5 Brpym = 5-Bromopyrimidine) mit seinen wabenartigen Schichten 2 I [CuSCN] chiral (monoklin P2 1 ) ist, weisen die dreidimensionalen Polymere 3 I [(CuSCN) 2 (l-pym)] (5) and 3 I [(CuSCN) 3 (l-4 Mepym)] (6) (4 Mepym = 4-Methylpyrimidin) polare Koordinationsnetzwerke (orthorhombisch Fdd2 bzw. monoklin Pc) auf. Das CuSCN-Geru È st von 5 besteht aus SCN-verbru È ckten 1 I [CuS]-Ketten, das von 6 aus miteinander verbundenen 2 I [CuSCN]-und 2 I [Cu 2 S(SCN)]-Schichten.