Platinum Metals Rev., 1985, 29, (3), 138
NEW PATENTS: July 1985
METALS AND ALLOYS
international business machines corp. U.S. Patent 4,476,454
New magnetoresistive materials are alloys of Ir with Fe, Ni and/or Co.
Permanent Magnet Materials
research institute of electric & magnetic alloys U.S. Patent 4,481,045
A permanent magnet having a high coercive force and large maximum energy product is an alloy of Fe with 25−40 at.% Pd or 19.5 at.% Pd and 0.1−27.5 at.% Ag.
Superconducting Type II Material
state university of new york research foundation U.S. Patent 4,485,152
A new superconducting type II Pd-Cu alloy hydride material includes a contiguous surface at which at least a portion of the alloy region contains H and at least a portion of the Pd region contains H.
reanal finomvegyszergyar British Appl. 2,144,768A
The electrodes of an apparatus for performing gel electrophoresis with polyacrylamide consist of spirals of Pt wire fixed in grooves on an electrode spool shaft.
Purifying Mixed-Cation Electrolyte
national research development corp. British Appl. 2,144,770A
A Pt wire coil or a Pt gauze is used as an anode in an apparatus for purifying an electrolyte containing cations of a less noble metal from contamination by cations of a more noble metal.
Electrolytic Cell Operation
imperial chemical industries p.l.c. European Appl. 135,314
An electrolytic cell is operated in tandem with a unit in which the electrolyte or the electrolysis products are treated in order to reduce the amount of high pressure pipework. The cell electrodes are preferably made of refractory metal coated with a platinum group metal.
Oxygen Evolving Electrodes
eltech systems corp. European Appl. 135,475
Electrodes suitable for the electrowinning of metals, for example, with the evolution of O2 are made from a valve metal base coated with a mixture of Ru and Mn oxides built up from several layers of varying composition (Ru:Mn = 1:1 to 1:6). The mixed oxide coating is resistant to peeling.
Olefin Electrochemical Conversion
british petroleum co. p.l.c. European Appl. 136,176
The electrochemical conversion of olefins to oxygenated products may take place on Pt or Os gas diffusion cathodes.
eisai co. ltd. European Appl. 137,367
An apparatus has sets of electrodes for detecting milk flows which may use Pt as the electrode material.
Electrodes for Electrolysis
nippon steel corp. U.S. Patent 4,477,316
Insoluble electrodes having few surface defects and a long life are prepared by coating an electroconductive, corrosion-resistant base metal, such as Ti or Ta, with at least one platinum group metal and applying a specified laser beam treatment.
Anode for Seawater Electrolysis
japan carlit co. ltd. U.S. Patent 4,479,864
An anode of improved efficiency and durability in the electrolysis of seawater consists of a Ti substrate coated with a mixture of 15−85% Pt, 5−35% Ir oxide and 10−15% Ru oxide.
Cobaltic Ion Regeneration
national research development council U.S. Patent 4,482,438
Aqueous Co(II) sulphate solutions formed in the oxidation of methylnaphthalene are converted back to Co (III) sulphate solutions by electrolysis within a Pt tube which acts as the anode.
permelec electrode ltd. U.S. Patent 4,484,999
Electrodes of increased durability consist of a conductive substrate, such as Ti, coated with an intermediate layer which is a mixture of TiO2 and/or SnO2 with Ta2O5, and then with a layer of active material containing at least one platinum group metal oxide, especially a mixture of Ru and Ir oxides.
Cathode for Electrolysis
ELECTRODEPOSITION AND SURFACE COATINGS
Metallisation of Glassy Bodies
licentia patent-verwaltungs g.m.b.h. European Appl. 132,784
Glassy surfaces and bodies, such as a soda-lime glass disc, is first coated with an In-Sn alloy layer (for example by CVD) on to which are deposited nuclei of Pd or another chemical plating metal. The surface is then reinforced, for example with Cu.
Electrode Coating with Reduced Overvoltage
bbc a.g. brown, boveri & cie European Appl. 133,468
A surface layer which reduces the overvoltage of an electrochemical electrode is a porous film of a compound of at least one transition metal, an optional Group IA and/or IIA metal and at least one of B, C, O, S, Se and Te. Typical layers consist of Ba2LaRuO6, BaFe0.1Ru0.9O3 and CeRu3C.
Coatings Resistant to Heat and Corrosion
u.s. secretary of the navy U.S. Patent 4,477,538
A material for use in hot, corrosive atmospheres is coated successively with Pt, Pd, Ir or Rh, then by MCrAlY alloy where M is Fe, Co or Ni and lastly by Pt, Pd, Ir or Rh.
Electrodeposition of Palladium-Silver Alloys
learonal inc. U.S. Patent 4,478,692
A bath for the electrodeposition of Pd-Ag alloys contains a soluble Pd compound such as (NH3)2Pd(NO2)2, a soluble Ag compound such as AgNO3 and sufficient strong acid to maintain the Pd and Ag compounds in solution without the addition of chloride or bromide ions.
Palladium Alloy Electroplating Bath
a.t. & t. bell laboratories U.S. Patent 4,486,274
An alloy of at least 10 mol% Pd with Ag, Cu and/or Ni is electrodeposited from a bath containing Pd as a complex with diaminopropane, diaminobutane, diaminohexane, tetramethyl ethylene-diamine or hydroxydiaminopropane.
w. c. heraeus g.m.b.h. German Offen. 3,317,493
Adherent, ductile, homogeneous coatings are obtained on metals such as Ni by electrodeposition from a bath containing, per litre, 5−50g Pd as (NH3)4PdBr2, 10−150g NH4Br, 10−150g sulphamic acid and/or ammonium sulphamate, 1−20g nicotinic acid and/or 0.1−0.5g nicotinamide at pH 6.5−10.
Rhodium Electroplating Solution
ordena trudovogo krasnogo znameni institut khimii i khimicheskoi tekhnologii an litovskoi ssr Russian Patent 1,109,481
Deposits of improved electrophysical properties are obtained from baths containing, per litre, 4−40g cis (triammino) (trinitro) Rh, (Rh(NH3)3 (NO2)3), 20−200g H2SO4 and 3−100g sulphamic acid.
LABORATORY APPARATUS AND TECHNIQUE
Engine Exhaust Gases Analysis
bl technology ltd. British Appl. 2,143,645A
An apparatus for detecting combustion-supporting constituents in exhaust gas comprises a heated Pt wire over which exhaust gas and butane are intermittently fed together. The heating effect on the wire due to any combustion of the butane in residual O2 in the exhaust gas gives a measure of uncombined O2 in the exhaust gas.
hochiki k.k. British Appl. 2,144,849A
A gas sensor comprises a laminate of a metal, such as Pd or Pt, capable of adsorbing and dissociating H2 gas and a gas which is a compound containing H, and a solid compound, such as W trioxide, Mo trioxide, TiO2, Ir hydroxide or V pentoxide, reducible by H atoms to change its photo absorption and, an optical means for detecting a change in photo absorption of the solid compound.
Bismuth Germanate Monocrystals
crismatec European Appl. 133,084
An Ir crucible is used in growing Bi germanate crystals in a neutral or oxidising atmosphere to avoid the formation of a Pt-Bi alloy in a Pt crucible.
Torque Sensor of the Non-Contact Type
toshiba k.k. European Appl. 136,086
Torque applied to a shaft is sensed magnetically using a strip of magnetic film wrapped round the shaft and made of (Co1-a-bFeaMb)zSixBy where M may be a platinum group metal, Au, Ag or a lanthanide.
lawrence electronics co. and julia f. lawrence U.S. Patent 4,477,778
A H2 detector having a H-permeable membrane between the atmosphere and the inside of a vacuum tube is made of a Pd alloy, preferably 75 Pd−25 Ag.
merck & co. inc. U.S. Patent 4,479,726
A portable apparatus for calibrating thermoelectric surface-temperature-measuring devices incorporates two standard Pt resistance probes.
Carbon Monoxide Indicator
e. i. du pont de nemours & co. U.S. Patent 4,482,635
An improved CO indicating composition consists of fumed SiO2 containing the dried residues of Pd sulphate, H2SO4 and ammonium molybdate. The SiO2 may be incorporated in a paper strip.
Induction Heated Crucible
philips patentverwaltung g.m.b.h. German Offen. 3,316,547
An induction-heated crucible for melting nonmetallic inorganic material such as a lanthanide metalgallium garnet may be partly made from Pt or Ir.
deutsche i.t.t. industries g.m.b.h. German Offen. 3,422,823
A gas sensor consists of a substrate such as Al2O3 coated with a gas-sensitive semiconductor oxide and then with a film of active metal, preferably Pt.
Palladium-Gold Brazing Alloys
shin-etsu chemical co. ltd. British Appl. 2,143,837A
An organopolysiloxane composition curable by u.v. or electron beam irradiation includes a Pt or Rh catalyst and optionally a lanthanide compound, such as Ce oxide or a compound of La, Nd or Sm.
british petroleum co. p.l.c. British Appl. 2,144,727A
Crystalline metallosilicates having catalytic and molecular sieving properties, of the MTN-type, are prepared using as template a six-membered heterocyclic compound having at least two hetero atoms selected from O and N. They may be ion exchanged or impregnated with a compound of Pt, Pd, Rh, Ir, Ru or Ag.
Combustion Plant Exhaust Gas Purification
ferdinand lentjes dampfkessel- & maschinenbau European Appl. 132,584
A fuel is burnt in a firing plant and the stack gases are first treated over a multifunctional catalyst to remove CO, unburnt hydrocarbons and NOx before the S present is oxidised. A Pt-Rh catalyst may be used.
Nitrogen Oxide Removal from Gases
hoechst a.g. European Appl. 135,033
In the waste gases of a nitric acid plant the NOx content may be reduced by reaction with an added olefin in the presence of a noble metal catalyst. In one example ethylene is added and the catalyst consists of Pt/Al2O3.
Siloxane Impregnation of Textiles
wacker chemie g.m.b.h. European Appl. 135,187
Platinum group metal catalysts are used in conventional siloxane compositions employed in a new process for impregnating organic fibre textiles.
Platinum Hydrodewaxing Catalyst
mobil oil corp. U.S. Patent 4,474,618
A preferred catalyst for the hydrodewaxing of lube oil consists of 0.2−1% highly dispersed Pt supported on ZSM-5 zeolite.
teledyne industries inc. U.S. Patent 4,474,739
A catalyst for the atmospheric oxidation of low concentrations of H2S or HCN in air consists of an Al2O3 carrier impregnated with Pd dichloride and Cu dichloride.
w. r. grace & co. U.S. Patent 4,476,246
A three-way catalyst for the purification of I.C.E. exhaust gases is made by impregnating an Al2O3 carrier with Ce oxide, Na oxide and Pt, Pd and/or Rh by a specified procedure.
Synthesis Gas Conversion Catalyst
standard oil co. U.S. Patent 4,476,247
A catalyst for the conversion of synthesis gas to a mixture of alkanes and alkanols preferably consists of a carrier such as alundum supporting about 5% of a compound of general formula MaRubCucM′dNxOy, where M is Na, K or Rb, M′ is Pt, Pd, Rh and/or Ir, a is 0.02–0.5, b, c are 0.5–3, and d is 0.05–0.5.
Hydrocarbon Reforming Catalyst
mobil oil co. U.S. Patent 4,477,590
A hydrocarbon-reforming catalyst is a mixture of a particulate carrier such as Al2O3 supporting Pt and Re and a particulate carrier such as Al2O3 impregnated with Ir and Re, prepared by a specified procedure.
Platinum Group Metal and Base Metal Catalysts—Lead Tolerant
johnson matthey & co. ltd. U.S. Patent 4,478,797
Exhaust gas emitted from an I.C. engine operating on a Pb-containing fuel can be oxidised using a catalyst with improved Pb-tolerance. The catalyst comprises one or more platinum group metals and WO3, TiO2 or NiMoO4 supported on a ceramic or metallic monolith coated with Al2O3.
Vegetable Oil Hydrogenation
uop inc. U.S. Patent 4,479,902
In the continuous selective reduction of vegetable oils over a fixed bed, the catalyst preferably consists of Pt or Pd supported on TiO2 and pre-activated in H2 at a temperature above about 325°C.
ste. francaise des produits pour catalyse pro-catalyse U.S. Patent 4,480,048
Improved moving-bed catalysts for hydrocarbon conversion reactions preferably consists of an Al2O3 carrier supporting 0.1−0.5% Pt or Ir, 0.4−1% Ti and 0.2−0.5% Mn, Tc or Re.
Exhaust Gas Catalyst
uop inc. U.S. Patent 4,480,050
In a process for making a catalyst for the oxidation of I.C.E. exhaust gases, a porous refractory oxide carrier (alumina) is impregnated with an aqueous solution of Li acetate to give a Li content of 0.1−0.8%, dried and calcined prior to impregnation with Pt, Pd or Rh.
bayer a.g. U.S. Patent 4,481,341
Compositions of good storage stability at room temperatures, curing rapidly at elevated temperature, consist of an unsaturated organopolysiloxane, a hydridopolysiloxane and a Pt catalyst finely dispersed in a solid silicone resin which melts or softens in the range 70−250°C.
Metal-Containing Active Carbon Products
standard oil co. (indiana) U.S. Patent 4,482,641
A high surface area, porous active C matrix, with metal or metals dispersed uniformly in it, is obtained by co-crystallising a metal salt or salts with an aromatic acid, phenol, thiol or aromatic amine, mixing the co-crystallite with a Group IA hydroxide and pyrolysing the product at 400−980°C. The preferred metals include Pt, Pd, Rh and Ag. The metal-carbon materials may be used as hydrocarbon conversion catalysts.
Double Bond Isomerisation Catalyst
mobil oil corp. U.S. Patent 4,482,752
A variety of organic compound conversions may be catalysed by a Group VIII metal, such as Pt or Rh, co-ordinated via an amino-Si function to an inorganic support, especially a zeolite.
benmol corp. U.S. Patent 4,483,259
In order to reduce the contents of CO, SOx and NOx in the flue gases from combustion of fossil fuels such as bituminous coal, the combustion catalyst preferably consists of a Ca aluminate, Ca aluminate cement, Ca titanate or Ba titanate adsorbant-support impregnated with Pt, Pd and Rh.
matsushita electric industrial co. ltd. and osaka gas co. ltd. U.S. Patent 4,483,673
A catalytic combustor of improved design for use in a gas heater incorporates a mat of heat-resistant fibres impregnated with Pt, Pd and/or Rh.
uop inc. U.S. Patent 4,483,767
A hydrocarbon-reforming catalyst consists of Pt and P or a P compound on an Al2O3 carrier.
I.C.E. Exhaust Gas Purification Catalyst
nippon shokubai kogyo co. ltd. U.S. Patent 4,483,940
A catalyst of improved thermal-shock resistance for use in the purification of I.C.E. exhaust gases is made by coating a monolithic ceramic honeycomb carrier with a water soluble organic compound of high molecular weight such as a saponified polyvinyl alcohol, and then with Al2O3, and impregnating with Pt, Pd and/or Rh.
Photodecomposition of Water
ciba-geigy corp. U.S. Patent 4,484,992
A catalyst for the production of H2 by photodecomposition of H2O in the presence of an ammonium of Group IA metal sulphide or sulphite consists of a finely particulate semiconductor powder carrier which is CdS, Cd sulpho-selenide or TiO2, at least partly coated with one or two of the platinum group metals, Ni, Ag and Au.
institut francais du petrole French Appl. 2,543,946
The hydrogenation of methyl formate to methanol is catalysed by supported Rh promoted with Sn, Ge and/or Pb.
Catalysts for Carboxylic Acid Production
hoechst a.g. German Offen. 3,318,210
In a process for making acetic, propionic and butyric acids simultaneously, synthesis gas is converted over a supported Rh catalyst promoted with a Group IA metal, preferably Li, and a specified transition or lanthanide metal, preferably Yb.
Ketone Production Catalysts
Carboxylic Acid Production
bp chemicals ltd. European Appl. 135,286
Acetic acid or another carboxylic acid is obtained by the rearrangement of methyl formate or a higher ester in the presence of an Ir catalyst, a halide promoter and a strong acid, for example, Ir trichloride, CH3I and methane sulphonic acid.
Acetic Acid Production
chemische werke huls a.g. European Appl. 135,776
Acetic acid is produced by the rearrangement of methyl formate in the presence of Rh metal, a Rh salt or a Rh complex; a halogen or halogen compound; an organic ligand, and chromium carbonyl and/or halide. One example shows the use of Rh chloride, Cr carbonyl, triethyl methyl ammonium iodide and CH3I as the catalyst.
bp chemicals ltd. U.S. Patent 4,474,959
The formation of quaternary ammonium formates from tertiary amines, H2 and CO2 in aqueous isopropanol is catalysed by Ru derivatives, such as RuCl3.3H2O or [Ru(CO)2Cl2]n.
general electric co. U.S. Patent 4,474,976
The formation of phenyl silanes from hydridosilanes and halogenated aromatic compounds such as bromobenzene or benzoyl chloride is catalysed by a t.phosphine complex of Pt, Pd, Rh or Ru.
Ruthenium Isobutyrate Catalysts
eastman kodak co. U.S. Patent 4,474,995
The formation of isobutyraldehyde from propylene, CO and H2 is catalysed by Ru2 (iBuCOO)4X.
ciba-geigy corp. U.S. Patent 4,476,305
Complexes of platinum group metals with polymerised 2-substituted-5-vinyl pyrimidines are useful catalysts in a variety of reactions. Pd complexes catalyse the transesterification of vinyl esters.
Mixed Metal Catalysts
produits chimiques ugine kuhlmann U.S. Patent 4,478,757
Catalysts for the formation of aromatic isocyanates from corresponding nitro compounds and CO are made by thermal decomposition of a supported complex M2M′(Cp)2(CO)6(PPh3)2, where M is Pd and M′ is Mo, Cr or W; or M is Pt and M′ is W.
Olefin Hydroxylation Catalyst
exxon research & engineering co. U.S. Patent 4,482,763
The hydroxylation of olefins with an organic hydroperoxide in water is enhanced by an Os compound and a halohydrocarbon, such as OsO4 and butyl iodide. A platinum group or transition metal halide may also be present.
sun tech inc. U.S. Patent 4,485,245/46
A catalyst for the hydrogenation of carboxylic acid anhydrides to esters or lactones is chosen from [RuCl (SnCl3) (PPh3)2], [Ru2Cl3 (SnCl3) (CO)2 (PPh3)4], [Ru2Cl3 (SnCl3) (CO)2 (PPh3)2 (Me2CO)2] and [RuH (SnCl3) (PPh3)3], optionally promoted with an amine.
Fuel Cell Catalyst Production
united technologies corp. British Appl. 2,146,044A
A ternary metal alloy catalyst is made by contacting a finely divided noble metal such as Pt supported on C black with a Group IV–VII transition metal compound and a Co compound, followed by heating and reduction in a N2 atmosphere.
psi star British Appl. 2,143,778A
A metal such as Pd or Cu is etched by forming a film of water on the surface of the metal and exposing the water-covered metal to gaseous NO2 to dissolve the metal.
international business machines corp. U.S. Patent 4,474,731
In a process for making sintered ceramics using an organic binder, a small amount of a Ni or Pd salt is incorporated in the mixture to ensure the absence of residual C in the final product.
konishiroku photo industry co. ltd. U.S. Patent 4,477,561
A Ag halide photographic material having a storage-stable wide latitude for exposure includes at least two layers containing a photosensitive Ag halide, optionally sensitised with Au and S, and a water-soluble compound, of mol.wt. not less than 100, of a platinum group metal. Preferred compounds are ammonium chloroplatinate, ammonium hexachloroiridate and potassium hexachlororhodate.
glaverbel and vertipack British Appl. 2,145,829A
Pt or Pt alloy electrodes are used in an apparatus for monitoring the redox state of elements in molten glass.
Glass Fibre Feeders
ELECTRICAL AND ELECTRONIC ENGINEERING
bicc p.l.c. British Appl. 2,144,559A
To reduce migration of potentially harmful H into an optical fibre of an optical cable, the cable incorporates a Pd wire to absorb H or the optical fibre itself may have a Pd coating.
Thermal Cut-Out Devices for Radiant Heaters
micropore international ltd. British Appl. 2,146,431A
A Group VIII metal such as Pt, Ir, or Au is used as a radiation-reflective coating material in a thermal cutout device for a radiant heater.
Matrix Print Head
international business machines corp. European Appl. 132,615
Electrolytic printing heads are made from stacked and laminated green ceramic sheets whose holes are filled with conductive paste to form electrodes. The surface is screen printed with a layer of RuO2. The electrodes are preferably made from a Ag-Pd powder.
Conductive Sheet for Recording Purposes
toray industries inc. European Appl. 134,117
Electrostatic recording is carried out using an organic polymer sheet coated with a layer of metal oxide and a layer of Pt, Pd, Rh, Ir, or Ru. The oxide layer may consist of In and Sn oxides.
Light-Duty Electrical Contact Material
a.t. & t. bell laboratories U.S. Patent 4,475,983
A light-duty contact material or reduced film resistance is made by powder-metallurgical techniques from a matrix material, preferably Cu, in which are dispersed particles of a harder conductive material such as Ru, Os, RuO2, Ru2B3, Ru2W3, Ru2Mo5, Re, etc.
Thick Film Resistor Composition
e.i. du pont de nemours & co. U.S. Patent 4,476,039
A stain-free thick film resistor composition preferably consists of 15−30% RuO2, 5−50% of a specified compound which will liberate O2 on heating, such as Ag2O or CoCrO4, 5−20% inorganic glass frit binder and 5−45% organic medium.
spire corp. U.S. Patent 4,477,921
A composite target for use in an X-ray lithography source tube includes at least one X-ray-generating layer of Cu, Al, Si, W, Mo, Ag, Pt, Pd or Rh; and a water-interface layer including a layer of material of high thermal conductivity, preferably Cu, coated on one side by a material of high melting point, preferably Ta, and on the other side by a material of good corrosion resistance, preferably Pd.
Capture of Solar Energy
yeda research & development co. ltd. U.S. Patent 4,478,699
A device using solar energy to convert CO2 and H2O to a mixture of formic acid, formaldehyde and methanol includes a layer of powdered photoactive material which may be Ru oxide or sulphide, among others.
chugai denki kogyo k.k. U.S. Patent 4,479,892
An electric contact material for use at high current density and/or high temperature consists of a substrate of Cu, Ni, Fe and/or Ag; a layer of Ag containing 2−20% finely dispersed particles of Sn, Sb, Zn, In, Cd and/or Bi oxide(s); and a surface layer of Pd or Au diffused into the Ag layer under pressure and at 700−900°C.
Electrochromic Display Devices
citizen watch co. ltd. U.S. Patent 4,482,216
By using two layers of electrochromic material with an additional electrode, a lower driving voltage is needed to achieve the same colour change. The first electrochromic material may be W oxide and the second is selected from Ir, Rh and Ni oxides.
Magnetic Recording Medium
t.d.k. electronics co. ltd. U.S. Patent 4,486,498
A magnetic recording medium consists of a substrate layer and at least one magnetic layer which is an alloy of Co with Zn, Rh or Ir in the ratios by weight for Co:Zn of 70:30–86:14, Co:Rh of 73:27–85:15 and Co:Ir of 75:25–90:10.
Contact for Solar Cells
national research development corp. British Appl. 2,144,330A
Immunogenic compositions consist of a peptide or protein material and OsO4, K permanganate or Ru oxide. Antibodies raised by the use of such compositions are of value in therapy and diagnosis, such as in snake venom vaccines.
e. i. du pont de nemours & co. European Appl. 137,457
Compounds for diagnostic or therapeutic applications are target-seeking biologically active molecules which are associated with metallothioneins containing trade-label metals such as the platinum group metals, Au and Ag, among others.
siemens a.g. U.S. Patent 4,477,314
An apparatus for the electrocatalytic determination of glucose, especially in blood, incorporates a platinised Pt electrode and a reference electrode.
Platinum Complexes for Cancer Treatment
otsuka chemical co. ltd. U.S. Patent 4,477,387
Compounds of increased activity in the treatment of cancer are complexes of Pt with a diamine, such as a cyclohexane-1,2-diamine or phenyl ethylene-diamine, and D-gluconic acid.
Dental Restoration Alloy
j. m. ney co. U.S. Patent 4,482,323
A casting alloy which offers good adhesion to fired porcelain contains 45−60% Pd, 25−45% Ag, 3−15% of a hardening component (Sn and/or In), 0.3−9% Zn, 0.1−1% Si, up to 0.5% of a grain refining agent (Re and/or Ir) and up to 5% of Cu, Mn, Ga and/or Ru. A typical alloy contains 55% Pd, 35% Ag, 9% Sn.
Antitumour Platinum Oligomers
f. rochon and p. kong French Appl. 2,541,284
Polycarboxylic acids are reacted with Pt iodide complexes of ammonia, a primary or secondary amine or pyridine to given oligomeric complexes, such as cisplatinum diammine cyclobutylamine benzene tetracarboxylate.