Pharmaceutical development of a parenteral lyophilized formulation of the investigational polymer-conjugated platinum anticancer agent AP 5280.

AP 5280 is a novel polymer-conjugated platinum anticancer agent showing promising in vitro and in vivo activity against solid tumors. The aim of this study was to develop a parenteral pharmaceutical dosage form for phase I clinical trials. AP 5280 drug substance was characterized by using a wide range of analytical techniques and showed excellent solubility in water. However, as aqueous solutions of AP 5280 proved to be labile upon sterilization by moist heat, it was decided to develop a lyophilized dosage form. Initially, glass vials were used as primary packaging, but this led to a high breakage rate, which could be completely prevented by the use of CZ resin vials. Stability studies to date show that the lyophilized product in glass vials is stable for at least 12 months when stored at 2-8 degrees C in the dark and the lyophilized product in CZ resin vials is stable for at least 6 months under these conditions. Photostability testing revealed photolability of AP 5280 drug substance and lyophilized product in both types of primary container, necessitating storage in the dark. The first clinical experiences indicate that the proposed formulation is fully applicable for use in the clinical setting.

Platinum(II)-based coordination compounds as nucleic acid labeling reagents: synthesis, reactivity, and applications in hybridization assays.

The synthesis, characterization, and molecular interactions of platinum(II) coordination compounds, which contain a distal nonradioactive reporter molecule, with mono- and polynucleotides are described. A [Pt(II)(en)(NH(2)(CH(2))(6)NH-tBoc)Cl](NO(3)) (en=ethylenediamine) entity has been coupled, after removal of the tBoc group, to a number of hapten and fluorophore molecules through succinimide derivatives. The influence of the various tethered reporter groups within these complexes on the reactivity towards guanosine 5'-monophosphate (5'-GMP), as a model for polynucleotide sequences, was investigated to shed light on the use of these reagents in hybridization assays. Reactivity turned out to be strongly dictated by the chemical nature of the distal reporter molecule present. At pH 7.0 the sequence of reactivity is cationic approximately aromatic (stacking) > neutral > anionic; there is approximately an order of magnitude difference between the fastest reacting complex (k=10.2 x 10(-2) M(-1) s(-1)) and the slowest reacting complex (k=0.93 x 10(-2) M(-1) s(-1)) under these conditions. Platination of an oligodeoxynucleotide (30-mer), dsDNA, or an RNA transcript, shows that a Pt/nucleotide ratio between 1:10 and 1:20 (established by using flameless atomic absorption spectroscopy) results in probes with excellent hybridization characteristics. In terms of applicability and detection limits these platinated nucleic acid probes perform equally well compared to conventionally generated nucleic acid probes, that is, through enzymatic incorporation of covalently labeled nucleotide triphosphates. Applications of these reagents to in situ hybridization assays and gene expression profiling on microarrays illustrate the potential of these monofunctional binding platinum triamine compounds.

Stability and compatibility of the investigational polymer-conjugated platinum anticancer agent AP 5280 in infusion systems and its hemolytic potential.

AP 5280 is a novel polymer-conjugated platinum anticancer agent currently undergoing phase I clinical trials. It is pharmaceutically formulated as a lyophilized product containing 200 mg platinum per dosage unit. The aim of this study was to determine the reconstitution and dilution fluid of choice, and to investigate the stability and compatibility of AP 5280 in solution under different storage conditions and with several container materials. Furthermore, the hemolytic potential of AP 5280 infusion solution was investigated. AP 5280 slowly released small platinum species in all solutions, although this release was enhanced in normal saline. Accordingly, 5% dextrose in water (D W) was selected for reconstitution and dilution of AP 5280. Container material [glass or polyvinylchloride (PVC)] did not influence the stability of AP 5280 in solution. Storage at refrigerated temperature (2-8 degrees C) marginally decreased the release rate of liberated platinum. The infusion solutions are compatible with the PVC infusion system and do not cause hemolysis. In conclusion, AP 5280 lyophilized product should be reconstituted and diluted to infusion concentration with D W, and administered within 8 h after preparation to ensure that less than 1.0% of the total platinum concentration is present as liberated platinum.

Structure determination of the [Fe(teec)(6)](BF(4))(2) metal complex from laboratory and synchrotron X-ray powder diffraction data with grid-search techniques.

The structure of the coordination compound [Fe(teec)(6)](BF(4))(2), hexa[1-(2-chloroethyl)tetrazole]iron(II) di(borotetrafluoride), has been determined using the grid-search techniques of the program suite MRIA. A Guinier-camera data set was used to determine the unit cell, the space group and to position the initial model. A high-resolution synchrotron powder data set was used to position a more detailed model using torsion-angle variation and to refine the structure leading to Rp = 0.0689, Rw = 0.0805 and GoF = 1.38. The crystal structure at room temperature shows the existence of two symmetry-equivalent iron(II) ions in the high-spin state.

Sterically hindered cisplatin derivatives with multiple carboxylate auxiliary arms: synthesis and reactions with guanosine-5'-monophosphate and plasmid DNA.

Two novel sterically hindered cisplatin derivatives with the ligand L=NH(2)C(CH(2)CH(2)COOH)(3) were prepared: cis-PtCl(2)L(2) and cis-PtCl(2)L(NH(3)). The starting compound for the syntheses was NH(2)C(CH(2)CH(2)COOtBu)(3), also known as a building block for dendrimers. cis-PtCl(2)L(2) was prepared from K(2)PtCl(4) in an unusual two-phase reaction in water-chloroform, followed by deprotection of the tert-butyl protective groups with formic acid to yield a water-soluble complex. The mixed-ligand compound cis-PtCl(2)L(NH(3)) was prepared from [PPh(4)][PtCl(3)(NH(3))] in methanol, with subsequent deprotection in formic acid. DNA-binding properties of the two compounds were investigated using the model base guanosine-5'-monophosphate (5'-GMP) and pBR322 plasmid DNA. While cisplatin [cis-PtCl(2)(NH(3))(2)] induced an unwinding of 12 degrees in pBR322 plasmid DNA, cis-PtCl(2)L(NH(3)) induced only 3 degrees unwinding, which is indicative of a monofunctional binding mode. Remarkably, cis-PtCl(2)L(2) did not induce any distortion in plasmid DNA, which strongly suggests that the compound does not bind to DNA. Test reactions with 5'-GMP, monitored by 1H and 195Pt NMR, confirmed that cis-PtCl(2)L(2) is unable to bind to DNA, whereas cis-PtCl(2)L(NH(3)) binds only one nucleotide. Apparently, binding of platinum to nucleotides at the coordination site cis with respect to the ligand L is prevented by steric crowding. Thus, cis-PtCl(2)L(NH(3)) must bind DNA monofunctionally at the trans position. Besides, both compounds have a chloride replaced by one of the carboxylate arms, forming a a seven-membered chelate ring. In theory, cis-PtCl(2)L(2) could also form a second chelate ring, but this was not observed.

Dinuclear alkyldiamine platinum antitumor compounds: a structure-activity relationship study.

Six related dinuclear trans-platinum complexes, with the formula [[trans-PtCl(2)(NH(3))(L)](2)(mu-H(2)N(CH(2))(n)NH(2))](2+) (L = pyridine, 2-picoline, 4-picoline; n = 4, 6) and chloride or nitrate anions, are compared with known cytotoxic dinuclear compounds (L = NH(3); n = 4, 6) that overcome cisplatin resistance. The cytotoxicity of the compounds was determined in L1210 murine leukemia and L1210/2, a cisplatin-resistant derivative. Unlike the L = NH(3) compounds, the substituted n = 4 compounds are more susceptible toward the resistance mechanisms in L1201/2. The n = 6 compounds, however, have comparable IC(50) values in both cell lines. In general, the substituted compounds are less cytotoxic than their NH(3) counterparts. After incubation with equimolar concentrations, the amount of platinum bound to cellular DNA was determined. The compounds show comparable binding, except for the sterically hindered 2-picoline compounds that bind significantly less. The amounts of platinum bound to DNA do not correlate with the cytotoxicity data. As DNA is considered to be the cellular target of platinum antitumor drugs, structural details of the DNA adducts probably account for the differences in cytotoxic activity.

Tuning the recovery of an Rh-containing catalyst with silica-based (poly) amine ion exchangers.

Highly efficient Rh-recovery from different adsorption media has been effected with silica-based (chelating) ion exchangers containing (poly) amine functionalities; recoveries have been found to correlate well with the stability of the metal-to-ligand complexes.

New insights in the cellular processing of platinum antitumor compounds, using fluorophore-labeled platinum complexes and digital fluorescence microscopy.

The cellular distribution and processing pathways of two platinum compounds, modeling the antitumor drug cisplatin (cDDP) in human osteosarcoma (U2-OS) cells is reported. A [Pt(en)Cl] entity has been covalently linked to a carboxyfluorescein diacetate (CFDA) moiety and to a dinitrophenyl (DNP) moiety. The two different constructs were administered to living cell cultures that were analyzed using digital fluorescence microscopy. The non-fluorescent CFDA construct becomes fluorescent after cellular uptake and subsequent acetate hydrolysis by esterases, and is therefore suitable to monitor platinum in living cells; the DNP construct can be visualized by immunocytochemistry and consequently serves as a control. Both complexes were readily internalized by the cells, and localized throughout the whole cell. After 2-3 h the complex accumulated in the nucleus, but 6-8 h after incubation a punctuate staining of a cytoplasmic region was observed, that persisted and became more pronounced after 24 h. The overall fluorescence in the cell decreased over time, implying a secretion of the platinum complex. Surprisingly, the accumulation remained visible after 72 h. Co-localization experiments with a Golgi apparatus-selective stain indicate the involvement of Golgi vesicles in intracellular processing of cisplatin-derived complexes. Immunocytochemical studies, using the DNP derivative, resulted in very similar images as obtained with the CFDA construct. CFDA-boc (a non-platinum-containing fluorescein derivative) was used as control: a faint staining throughout the whole cell was observed. Cisplatin-resistant U2-OS/Pt cells showed staining patterns very similar to the U2-OS cells using both platinum constructs. This study illustrates that only a very small portion of the platinum complex eventually remains bound to DNA, as after 24 h no significant fluorescence could be observed in the nucleus. Cisplatin-derived complexes with fluorescent tags afford a new insight into the cellular processing of these complexes and therefore may contribute to further unraveling of the mechanism of platinum antitumor complexes.

Reaction of DNA oligonucleotides with [Pt(dien)GSMe]2+ (GSMe = S-methylated glutathione) and cis-[Pt(NH3)2(GSMe)2]2+: evidence of oligonucleotide platination via sulfur-coordinated platinum intermediates.

To study the possibility of DNA platination via platinum-sulfur coordinated intermediates, the reactions of the complexes [Pt(dien)GSMe]2+ (GSMe=S-methylated glutathione) and cis-[Pt(NH3)2(GSMe)2]2+ with the synthetic oligonucleotides d(ATATGCATAT), d(ATTACCGGTAAT), and d(ATCCTATTTTTTTTAGGAT) have been investigated. The reactions were studied using FPLC, NMR, and mass spectrometry. It was found that the sulfur atom of the platinum-thioether adduct is substituted by these oligonucleotides. For the reactions with [Pt(dien)GSMe]2+ at 310 K, half-lives were determined to be t 1/2 =147+/-7 h for d(ATATGCATAT), t 1/2 =84+/-4 h) for d(ATTACCGGTAAT), and t 1/2 = 21+/-1 h for d(ATCCTATTTTTTTTAGGAT. This study clearly shows that it is indeed possible for oligonucleotides to be platinated via Pt-thioether coordinated intermediates. The rates at which such substitutions occur, however, makes it improbable that such a mechanism contributes significantly to the antitumor activity of cisplatin.

Binding of nitrite and its reductive activation to nitric oxide at biomimetic copper centers.

The reactivity of nitrite towards the copper(II) and copper(I) centers of a series of complexes with tridentate nitrogen donor ligands has been investigated. The ligands are bis[(1-methylbenzimidazol-2-yl)methyl]amine (1-bb), bis[2-(1-methylbenzimidazol-2-yl)ethyl]amine (2-bb), and bis[2-(3,5-dimethyl-1-pyrazolyl)ethyl]amine (ddah) and carry two terminal benzimidazole (1-bb, 2-bb) or pyrazole (ddah) rings and a central amine donor residue. While 2-bb and ddah form two adjacent six-membered chelate rings on metal coordination, 1-bb forms two smaller rings of five members. The binding affinity of nitrite and azide to the Cu(II) complexes (ClO4- as counterion) has been determined in solution. The association constants for the two ligands are similar, but nitrite is a slightly stronger ligand than azide when it binds as a bidentate donor. The X-ray crystal structure of the nitrite complex [Cu(ddah)(NO2)]ClO4 (final R=0.056) has been determined: triclinic P1space group, a=8.200(2) A, b=9.582(3) A, c=15.541(4) A. It may be described as a perchlorate salt of a "supramolecular" species resulting from the assembly of two complex cations and one sodium perchlorate unit. The copper stereochemistry in the complex is intermediate between SPY and TBP, and nitrite binds to Cu(II) asymmetrically, with Cu-O distances of 2.037(2) and 2.390(3) A and a nearly planar CuO2N cycle. On standing, solutions of [Cu(ddah)(NO2)]ClO4 in methanol produce the dinuclear complex [Cu(ddah)(OMe)]2(ClO4)2, containing dibridging methoxy groups. In fact the crystal structure analysis (final R=0.083) showed that the crystals are built up by dinuclear cations, arranged on a crystallographic symmetry center, and perchlorate anions. Electrochemical analysis shows that binding of nitrite to the Cu(II) complexes of 2-bb and ddah shifts the reduction potential of the Cu(II)/Cu(I) couple towards negative values by about 0.3 V. The thermodynamic parameters of the Cu(II)/Cu(I) electron transfer have also been analyzed. The mechanism of reductive activation of nitrite to nitric oxide by the Cu(I) complexes of 1-bb, 2-bb, and ddah has been studied. The reaction requires two protons per molecule of nitrite and Cu(I). Kinetic experiments show that the reaction is first order in [Cu(I)] and [H+] and exhibits saturation behavior with respect to nitrite concentration. The kinetic data show that [Cu(2-bb)]+ is more efficient than [Cu(1-bb)]+ and [Cu(ddah)]+ in reducing nitrite.

Solid-Phase Synthesis of a Monofunctional trans-a(2)Pt(II) Complex Tethered to a Single-Stranded Oligonucleotide.

Cross-linking ability is possible with the oligonucleotide-tethered, monofunctional trans-Pt(II) complex shown. It was synthesized by a novel solid-phase approach comprising conjugation of immobilized tetrathymidylic acid with a trans-a(2)Pt(II) building unit, ammonolysis, and transformation of the resulting complex (R=1-N-cyclohexylmethylthyminate) into the chloro derivative (R=Cl). a=NH(2)CH(3), T=thymine.

Synthesis, characterization, and crystal structure of alpha-[Ru(azpy)2(NO3)2] (azpy = 2-(phenylazo)pyridine) and the products of its reactions with guanine derivatives.

The synthesis and characterization of alpha-[Ru(azpy)2(NO3)2], 1, are reported (azpy is 2-(phenylazo)pyridine; alpha indicates the isomer in which the coordinating pairs ONO2, N(py), and N(azo) are cis, trans, and cis, respectively). The solid-state structure of 1 has been determined by X-ray crystallography. Crystal data: orthorhombic a = 15.423(5) A, b = 14.034(5) A, c = 10.970(5) A, V = 2374(2) A3, space group P2(1)2(1)2(1) (No. 19), Z = 4, Dcalc = 1.655 g cm-3. The structure refinement converged at R1 = 0.042 and wR2 = 0.118 for 3615 unique reflections and 337 parameters. The octahedral complex shows monodentate coordination of the two nitrate ligands. The Ru-N(azo) bond distances (2.014(4) and 1.960(4) A), slightly shorter than the Ru-N(py) bonds (2.031(4) and 2.059(4) A), agree well with the pi-back-bonding ability of the azo groups. The binding of the DNA-model bases 9-ethylguanine (9egua) and guanosine (guo) to 1 has been studied and compared with previously obtained results for the binding of model bases to the bis(bipyridyl)ruthenium(II) complex. The ligands 9egua and guo appear to form monofunctional adducts, which have been isolated as alpha-[Ru(azpy)2(9egua)Cl]PF6, 2, alpha-[Ru(azpy)2(9egua)(H2O)]-(PF6)2, 3, alpha-[Ru(azpy)2(guo)(H2O)](PF6)2, 4, and alpha-[Ru(azpy)2(guo)Cl]Cl, 5. The orientations of 9egua and guo in these complexes have been determined in detail with the use of 2D NOESY NMR spectroscopy. In 2 and 5, H8 is directly pointed toward the coordinated Cl, whereas, in 3 and 4, H8 is wedged between the pyridine and phenyl rings. The guanine derivatives in the azpy complexes can have more orientations than found for related cis-[Ru(bpy)2Cl2] species. This fluxionality is considered to be important in the binding of the alpha-bis(2-(phenylazo)pyridine)ruthenium(II) complex to DNA. In complex 1, ruthenium is the chiral center and in the binding to guanosine, two diastereoisomers each of adducts 4 and 5 have been clearly identified by NMR spectroscopy.

New antitumor-active azole-bridged dinuclear platinum(II) complexes: synthesis, characterization, crystal structures, and cytotoxic studies.

Three new derivatives of the cytotoxic azole-bridged dinuclear platinum(II) complex [(cis-Pt(NH3)2)2(mu-OH)(mu-pz)][NO3]2 (1) have been prepared and structurally characterized. Their formulas are [(cis-Pt(NH3)2)2(mu-OH)(mu-1,2,3-ta)][NO3]2 (2) (1,2,3-ta = 1,2,3-triazolate), [(Pt(R,R-dach))(mu-OH)(mu-pz)(Pt(S,S- dach))][NO3]2 (3) (dach = 1,2-diaminocyclohexane, pz = pyrazolate), and [(Pt(R,R-dach))(mu-1,2,3- ta)2(Pt(S,S-dach))][NO3]2 (4). The compounds were characterized by 1H, 13C, and 195Pt NMR spectroscopy, and elemental analysis, and their crystal structures were determined. Relevant data for 2: triclinic, space group P1, a = 8.5225(15) A, b = 9.1977(18) A, c = 9.9771(7) A, alpha = 66.988(10) degrees, beta = 75.423(9) degrees, gamma = 67.321(13) degrees, Z = 2. 3: orthorhombic, space group Pca2(1), a = 17.7653(3) A, b = 12.4076(3) A, c = 10.7091(3) A, Z = 4. 4: orthorhombic, space group Pbca, a = 13.8944(1) A, b = 17.8668(1) A, c = 20.7647(2) A, Z = 8. In the crystal structures of 2, and 3, the intramolecular distances between the two Pt atoms are 3.4411(6) and 3.4873(5) A, and the dihedral angles between the platinum coordination planes are 14.1(3) and 9.3(4) degrees, respectively. In 2, an intramolecular hydrogen bond is observed between N9 of the ammine ligand and the noncoordinated nitrogen atom (N3) of the triazole ring (N9...N3: 2.962(10) A). 4 has a boat-form structure, and the two coordination planes cross at 83.64(10) degrees. A cytotoxicity assay of these dinuclear platinum(II) compounds on human tumor cell lines was performed. In most of the cell lines, 1 and 2 showed much higher cytotoxicity than those of cisplatin. On the other hand, 3 was found to be moderately active, and 4 was found only marginally cytotoxic. Implications of these findings are discussed in the context of a structure-activity relationship.

Tuning the rotational behavior of lopsided heterocyclic nitrogen ligands (L) in octahedral cis-[Ru(bpy)2(L)2](PF6)2 complexes. A variable-temperature 1H NMR study.

In this paper are presented the syntheses, characterizations, and dynamic solution behaviors of three cis-[Ru(bpy)2(L)2] (bpy = 2,2'-bipyridine) complexes, 1-3, in which L represents the monodentate ligands 1-methylimidazole (MeIm), 1,2-dimethylimidazole (Me2Im), and 1-methylbenzimidazole (MeBim), respectively. Because of their different steric properties, these three monodentate ligands yield complexes that show quite different fluxional behaviors in solution. These behaviors are studied with several 1H NMR techniques at various temperatures between -95 and degrees C. The 1H NMR spectra of 1, which has the smallest monodentate ligand of the three used, indicate the complex to be in fast exchange (i.e., the imidazoles rotate around their Ru-N axes) at all recording temperatures. The sterically more demanding ligands, Me2Im and MeBim, in 2 and 3, respectively, are in fast exchange at 55 degrees C and in slow exchange at low temperatures, showing three different atropisomers: two head-to-tail (HT) isomers and one head-to-head (HH) isomer. The newly synthesized bidentate ligand 1,2-bis-(1-methyl-2-benzimidazolyl)ethane (mdbz) forms the complex cis-[Ru(bpy)2(mdbz)](PF6)2 (4), in which the two benzimidazole moieties are constrained and relatively fixed. The two tethered benzimidazoles in 4 cannot rotate around their Ru-N axes, and therefore 4 is a good model for the main HT isomer of 3.

Direct determination of the single-ion anisotropy in a one-dimensional magnetic system by high-field EPR spectroscopy; synthesis, EPR, and X-ray structure of NixZn1-x(C2O4)(dmiz)2.

The synthesis, X-ray structure, and EPR measurements of the integer-spin linear-chain antiferromagnet [Ni(ox)(dmiz)2] (where ox = C2O4(2-) and dmiz = 1,2-dimethylimidazole) are presented. The sign and size of the single-ion zero field splitting (Zfs) of the divalent Ni have been determined by high field/high-frequency EPR spectroscopy. The spectra of powder samples of the derivatives [NixZn1-x(C2O4)(dmiz)2] for x = 0.09 and 0.07, at frequencies ranging from 110 to 440 GHz allowed the accurate determination of the zfs parameters D and E, with D = 1.875(4) cm(-1) and E = 0.38 cm(-1). The X-ray structure has been determined from measurements on a single crystal with x = 0.07. Structural parameters are as follows: a = 14.5252(7) A, b = 12.1916(8) A, c = 8.6850(8) A,beta = 97.460(6)degrees in space group C2/c. The zigzag chain contains octahedrally coordinated metal ions with two cis-oriented N-coordinated dmiz ligands and two cis-oriented, tetradentate bridging oxalato(2-) ligands, together resulting in a MN2O4 donor set. The structure was refined to a conventional R value of 0.073 for 1,051 observed reflections. Zn-O distances are 2.167(5) A and Zn-N = 2.098 A. Coordination angles vary for cis angles from 78.4 to 100.7 degrees, with trans angles varying from 163.9 degrees to 165.5 degrees.

Trinuclear N,N-bridged copper(II) complexes involving a Cu3OH core: [Cu3(mu 3-OH)L3A(H2O)2]A.(H2O)x (L = 3-acetylamino-1,2,4-triazolate; a = CF3SO3, NO3, ClO4; x = 0, 2) synthesis, X-ray structures, spectroscopy, and magnetic properties.

The reaction of Haat [Haat = (3-acetylamino-1,2,4-triazole)] with aquated Cu(CF3SO3)2, Cu(NO3)2, and Cu(ClO4)2, respectively, in water results in the trinuclear complexes [Cu3(OH)(aat)3(CF3SO3)(H2O)2](CF3SO3) (1), [Cu3(OH)(aat)3(NO3)(H2O)2](NO3).(H2O)2 (2), and [Cu3(OH)(aat)3(ClO4)(H2O)2](ClO4) (3). The synthesis, X-ray structure, and magnetic and spectroscopic properties of the three title complexes are described. The cation of the three complexes is trinuclear with a Cu3OH skeleton which has the N-N diazine grouping of a triazole ring as bridge between each pair of copper atoms. The Cu3OH units have an average Cu-O distance of 1.991(6) (1), 2.000(6) (2), and 2.007(6) (3) A, an average Cu-Cu' distance of 3.355(2) (1), 3.341(1) (2), and 3.371(3) (3) A, and an average Cu-O-Cu' angle of 114.6(3) degrees (1), 112.4(2) degrees (2), and 115.4(3) degrees (3). The existence of the Cu3OH fragment is confirmed by a pseudotetrahedral oxygen environment, by detection of the OH hydrogen atom, and by stoichiometry. In the trinuclear unit the metal ions show, in the first approximation, a pseudo-square-planar pyramidal environment forming a CuN2O3 chromophore; three of the basal positions are occupied by N,N,O aat ligand atoms, the fourth one is occupied by the oxygen of the central OH group, and the apical site is occupied by an oxygen atom from a water molecule in the case of two of the copper(II) atoms and by an oxygen atom from the coordinating anion in the case of the third metal ion. The three compounds exhibit strong antiferromagnetic interaction, with similar J constants [J = -197.7 (1), J = -190.9 (2), J = -198.2 (3) cm-1], reaching complete spin coupling at ca. 75 K (1)/55 K (2)/95 K (3). At very low temperature the magnetic moment (magnetic susceptibility) falls below that expected for one unpaired electron. Magnetic parameters are discussed on the basis of the structural results and compared with those reported in the literature for related trimeric Cu(II) compounds with N-O or N-N peripheral bridges. Solid state EPR spectra of the three complexes recorded at liquid N temperature show axial signals. Crystal data: C14H20Cu3F6N12O12S2 (1) (Mw = 917.16) crystallizes in the monoclinic space group, P2(1)/c, Z = 4, with cell dimensions a = 13.080(2) A, b = 17.202(2) A, c = 13.840(2) A, beta = 92.40(1) degrees, and V = 3111.3(7) A3, Dcalcd = 1.958 Mg m-3; the final agreement values were R1 = 0.0582 and wR2 = 0.1462 for 7107 unique reflections. C12H24Cu3N14O14 (2) (Mw = 779.07) crystallizes in the triclinic space group, P1, Z = 2, with cell dimensions a = 9.647(2) A, b = 9.985(2) A, c = 15.314(2) A, alpha = 84.080(10), beta = 87.694(10), gamma = 65.030(10) degrees, and V = 1330.1(4) A3, Dcalcd = 1.945 Mg m-3; the final agreement values were R1 = 0.0397 and wR2 = 0.0950 for 7728 unique reflections. C12H20Cl2Cu3N12O14 (3) (Mw = 817.92) crystallizes in the monoclinic space group, P2(1)/a, Z = 4, with cell dimensions a = 14.238(5) A, b = 16.387(6) A, c = 11.678(4) A, gamma = 90.45(2) degrees, and V = 2724.6(18) A3, Dcalcd = 1.994 Mg m-3; the final agreement values were R1 = 0.0616 and wR2 = 0.1279 for 4038 unique reflections.