A Homologous Series of Homoleptic Zinc Bis(1,4-di-tert-butyl-1,4-diaza-1,3-butadiene) Complexes: K(x)[Zn(t-BuNCHCHN-t-Bu)(2)], Zn(t-BuNCHCHN-t-Bu)(2), and [Zn(t-BuNCHCHN-t-Bu)(2)](OTf)(x) (x = 1, 2).

A homologous series of mono- and dicationic, neutral, and mono- and dianionic zinc diazabutadiene complexes, K(x)[Zn(t-BuNCHCHN-t-Bu)(2)], Zn(t-BuNCHCHN-t-Bu)(2), and [Zn(t-BuNCHCHN-t-Bu)(2)](OTf)(x) (x = 1, 2), have been prepared and isolated in pure form. The crystal structures of the mono- and dicationic as well as of the monoanionic complexes are reported. In this series, the formal charge on the t-BuNCHCHN-t-Bu ligands ranges from -2 to +2, and the way in which the molecular geometry of the ligands varies with the charge is discussed.

High Superoxide Dismutase Activity of a Novel, Intramolecularly Imidazolato-Bridged Asymmetric Dicopper(II) Species. Design, Synthesis, Structure, and Magnetism of Copper(II) Complexes with a Mixed Pyrazole-Imidazole Donor Set.

A new dinucleating ligand, 1,5-bis(1-pyrazolyl)-3-[bis(2-imidazolyl)methyl] azapentane (Hbpzbiap), containing pyrazoles and imidazoles has been designed and synthesized. The synthesis and characterization of the copper complexes with the ligand Hbpzbiap and its dehydronated form are described. This study is aimed at modeling the active site of copper-zinc superoxide dismutase (SOD).

5-HT1A-versus D2-receptor selectivity of flesinoxan and analogous N4-substituted N1-arylpiperazines.

We investigated the structural requirements for high 5-HT1A affinity of the agonist flesinoxan and its selectivity versus D2 receptors. For this purpose a series of arylpiperazine congeners of flesinoxan were synthesized and evaluated for their ability to displace [3H]-8-OH-DPAT and [3H]spiperone from their specific binding sites in rat frontal cortex homogenates and rat striatum, respectively. Variations were made in the N4-substituent and the arylpiperazine region.

N6,C8-distributed adenosine derivatives as partial agonists for adenosine A1 receptors.

The synthesis and biological evaluation of N6, C8-disubstituted derivatives of adenosine as potential partial agonists for adenosine receptors is described. Via three routes, two series of compounds were prepared, viz., N6-cyclopentyladenosine derivatives 3a-e and C8-(cyclopentylamino)adenosine analogs 3e and 9a-d, respectively.

Monodentate sigma-N and Bidentate sigma-N,sigma-N' Coordination of 1,1-Bis((N-p-tolylimino)diphenylphosphoranyl)ethane, CHCH(3)(PPh(2)=NC(6)H(4)-4-CH(3))(2), to Platinum(II).

The new ligand, 1,1-bis((N-p-tolylimino)diphenylphosphoranyl)ethane (1,1-BIPE), 1, has been synthesized by means of a Staudinger reaction of 1,1-bis(diphenylphosphino)ethane (1,1-dppe) with 2 equiv of p-tolylazide. Bridge-splitting reactions of Pt(2)Cl(4)(PR(3))(2) with 1 readily afforded sigma-N monodentate complexes, [PtCl(2)(PR(3)){1,1-BIPE-sigmaN}] (2a, PR(3) = PEt(3); 2b, PR(3) = PMe(2)Ph). Conversion of 2 into the six-membered platinacycle [PtCl(PR(3)){1,1-BIPE-sigmaN,sigmaN'}](+)[X](-) (3) (X = Cl, PtCl(3)(PR(3)), BF(4)) took place after prolonged stirring, its reaction rate being strongly dependent on the type of phosphine (>5 days for 2ain the presence of NaBF(4), 1 h for 2b) and the metal-to-ligand ratio.