Professor Eberhard Hoyer zum 70. Geburtstag gewidmet. Inhaltsu È bersicht. Eine Serie von 1,2-Diselenoquadratatometallaten vom Typ [M(dssq) 2 ] 2± (M = Pd 2+ , Pt 2+ , Cu 2+ , Ni 2+ , Zn 2+ C Ë d 2+ , Pb 2+ , VO 2+ ) ist durch direkte Umsetzung entsprechender Metallsalze mit Dikalium-1,2-diselenoquadratat in sauerstofffreiem Wasser unter Argon zuga È nglich. Der Kupfer(II)-Komplex [Cu(dssq) 2 ] 2± und der Oxovanadium(IV)-Komplex [VO(dssq) 2 ] 2± konnten in Lo È sung EPR-spektroskopisch nachgewiesen werden (Parameter: [Cu(dssq) 2 ] 2± : g 0 = 2,073; a Cu 0 = ±76,0´10 ±4 cm ±1 , a Se 0 = 47,0´10 ±4 cm ±1 , [VO(dssq) 2 ] 2± : g 0 = 1,986; a V 0 = 74,9´10 ±4 cm ±1 ). Die Komplexe Bis(tetraphenylphosphonium)[bis(1,2-diselenoquadratato)nickelat(II)], (Ph 4 P) 2 [Ni(dssq) 2 ], und Bis(tetraphenylphosphonium)[bis(1,2-diselenoquadratato)zinkat(II)], (Ph 4 P) 2 [Zn(dssq) 2 ], wurden durch Ro È ntgenkristallstrukturanalyse charakterisiert. Der quadratisch-planare Ni II -Komplex (Ph 4 P) 2 [Ni(dssq) 2 ] kristallisiert in der monoklinen Raumgruppe P2 1 /n mit den Gitterkonstanten: a = 11,1472(8) A Ê , b = 15,331(1) A Ê , c = 14,783(1) A Ê , b = 94,441(1)°u nd Z = 2. Der Zn II -Komplex (Ph 4 P) 2 [Zn(dssq) 2 ] ist tetraedrisch koordiniert und kristallisiert in der monoklinen Raumgruppe P2 1 /c mit den Gitterkonstanten: a = 9,4238(1) A Ê , b = 18,5823(3) A Ê , c = 29,5309(5) A Ê , b = 96,763(1)°und Z = 4. Bis(1,2-diselenosquarato) Metalates Abstract. A series of 1,2-diselenosquarato metalates [M(dssq) 2 ] 2± (M = Pd 2+ , Pt 2+ , Cu 2+ , Ni 2+ , Zn 2+ , Cd 2+ , Pb 2+ , VO 2+ ) was available by direct synthesis from the appropriate metal salt with dipotassium 1,2-diselenosquarate in deoxygenized water under an argon athmosphere. The copper(II)-complex, [Cu(dssq) 2 ] 2± , and the oxovanadium(IV)complex, [VO(dssq) 2 ] 2± , were identified in solution by EPR spectroscopy (parameters: [Cu(dssq) 2 ] 2± : g 0 = 2.073; a Cu 0 = ±76.01 0 ±4 cm ±1 , a Se 0 = 47.0´10 ±4 cm ±1 ; [VO(dssq) 2 ] 2± : g 0 = 1.986; a V 0 = 74.9´10 ±4 cm ±1 ). The complexes bis(tetraphenylphosphonium)[bis(1,2-diselenosquarato)nickelate(II)], (Ph 4 P) 2 -[Ni(dssq) 2 ], and bis(tetraphenylphosphonium)[bis(1,2-diselenosquarato)zincate(II)], (Ph 4 P) 2 [Zn(dssq) 2 ], were characterized by X-ray structure analysis. The square-planar Ni II complex (Ph 4 P) 2 [Ni(dssq) 2 ] crystallizes in the monoclinic spacegroup P2 1 /n with the unit cell parameters a = 11.1472 (8) A Ê , b = 15.331(1) A Ê , c = 14.783(1) A Ê , b = 94.441(1)°a nd Z = 2. The Zn II -complex (Ph 4 P) 2 [Zn(dssq) 2 ] is tetrahedral coordinated and crystallizes in the monoclinic spacegroup P2 1 /c with the unit cell parameters a = 9.4238(1) A Ê , b = 18.5823(3) A Ê , c = 29.5309(5) A Ê , b = 96.763(1)°and Z = 4.