5‐Cyanotetrazolate as a Ligand and Linker in Copper(II) Complexes and Coordination Polymers. Issue 18 (15th May 2013)

• Record Type: Journal Article
• Authors: Szafranowska, Barbara; Beck, Johannes
• Is Part Of: European journal of inorganic chemistry. Issue 18(2013)
• Page Start: 3167
• Page End: 3177
• Publication Date: 2013-05-15
• Subjects: Nitrogen heterocycles -- Copper -- Coordination polymers -- Magnetic properties; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201201483
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract: 5‐Cyanotetrazole readily forms from (CN)2 and HN3 . The coordination abilities of the 5‐cyanotetrazolate anion N4 CCN – (ctz) towards Cu II ions were examined and a series of complexes and coordination polymers were synthesized and characterized by single‐crystal structure analyses: PPh4 [Cu(ctz)3 ] (1 ), [Cu(ctz)2 (bipy)] (2, bipy = 2, 2′‐bipyridine), [CuCl(py)4 ](ctz)· 2py (3, py = pyridine), [Cu2 (ctz)6 Cu(CH3 CN)2 (H2 O)2 ]· 2CH3 CN (4a ), [Cu2 (ctz)6 Cu(H2 O)3 {(CH3 )2 CO}]· 3(CH3 )2 CO (4b ), [Cu(ctz)2 (py)4 ] (5 ), [Cu2 (ctz)4 (bipy)2 ] (6 ) and [Cu2 (ctz)2 (tpm)2 (NO3 )]NO3 [7, tpm = tris(pyrazol‐1‐yl)methane]. As ctz is a multidentate linker, additional neutral coligands such as monodentate py, bidentate bipy and tridentate tpm ligands were used to avoid the formation of noncrystalline polymers. The structures of1 –7 reflect the versatile coordination abilities of ctz in the various types of coordination environments of the Cu II ions and dimensionalities of the linkages. The structures represent 1D chain motifs (1, 2 and3 ), 2D layered structures (4a and4b ), mononuclear (5 ) and dinuclear complexes (6 and7 ). Magnetic coupling phenomena were detected by susceptibility measurements of1, 4a, 6 and7, which were fitted to the magnetic models according to antiferromagnetic spin‐pairing of two S = 1/2 systems (Bleaney–Bowers) for6 ( J = –0.53 cm –1 ) and7 ( J = –2.91 cm –1 ), to the ferromagnetic high‐temperature series expansion based on the Baker 1D ( S = 1/2) chain model for1 ( J = +14.4 cm –1 ) and to the Néel model of ferrimagnetism for4a . The diverse magnetic interactions between the Cu 2+ sites are communicated by the bridging ctz anions. Abstract : Cyanotetrazolate (ctz) is a versatile ligand towards Cu II ions and allows different kinds of linkage. Eight complexes and coordination polymers are presented with structures representing 1D chain motifs, 2D layered structures, mononuclear and dinuclear complexes. The complexes show different magnetic coupling phenomena at low temperatures.