484-11-7

Basic information

• Product Name: Neocuproine
• Synonyms: TIMTEC-BB SBB008718;NEOCUPROINE REAG;NEOCUPROINE;10-Phenanthroline,2,9-dimethyl-1;2,9-dimethyl-10-phenanthroline;2,9-Dimethyl-o-phenanthroline;2,9-Dimethylphenanthroline;Neo-Cuproin
• CAS NO: 484-11-7
• Molecular Formula: C₁₄H₁₂N₂
• Molecular Weight: 208.26
• EINECS: 207-601-9
• Product Categories: Analytical Chemistry;Chelating Reagents;Phenanthrolines
• Mol File: 484-11-7.mol
• Article Data: 13

Chemical Properties

• Melting Point: 159-164 °C
• Boiling Point: 337.46°C (rough estimate)
• Flash Point: 159.7 °C
• Appearance: white to beige/
• Density: 1.1345 (rough estimate)
• Vapor Pressure: 2.89E-05mmHg at 25°C
• Refractive Index: 1.6152 (estimate)
• Storage Temp.: Store at +15°C to +25°C.
• Solubility: methanol: 0.1 g/mL, clear
• PKA: 6.01±0.30(Predicted)
• Water Solubility: slightly soluble
• Sensitive: Light Sensitive
• Merck: 6449
• CAS DataBase Reference: Neocuproine(CAS DataBase Reference)
• NIST Chemistry Reference: Neocuproine(484-11-7)
• EPA Substance Registry System: Neocuproine(484-11-7)

Safety Data

• Hazard Codes: Xi,Xn
• Statements: 36/37/38-20/21/22-22
• Safety Statements: 26-36/37/39-36-24/25
• WGK Germany: 3
• RTECS: SF8380000
• TSCA: Yes
• Hazardous Substances Data: 484-11-7(Hazardous Substances Data)

Usage

Chemical Properties

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Uses

Different sources of media describe the Uses of 484-11-7 differently. You can refer to the following data:
1. Due to the steric hindrance of the methyl groups attached to the carbon atoms adjacent to the nitrogen donor atoms of phenanthroline, the reagent does not give the low spin vivid red complex characteristic of phenanthroline derivatives with iron(II). However, in the presence of reducing agents it reacts with copper to give a copper(I) complex of composition MA2 and of tetrahedral symmetry. This chelate is insoluble in water and can be extracted by chloroform in which the absorption maximum of the complex appears at 457 nm. In this way the concentration of the complex can be measured. The method is suitable for the determination of copper in iron, manganese and vanadium ores even in the presence of aluminium, germanium, titanium and silicon. Neocuproine is today considered one of the most selective reagents. Unfortunately, it is rather expensive. 2,3-bis-(2-pyridyl)quinoxaline, prepared by Belcher et al. by condensation of o-diketone, 2,2'-dipyridyl and 0-phenylenediamine(44) contains the functional grouping characteristic of cuproine; it is quite suitable for the determination of copper and it is cheap. Starting with various substituted o-phenylene-diamines Belcher synthesized 25 different quinoxaline derivatives, of which 2,3-bis-[2-(-methyl)-pyridyl)]quinoxaline proved to be identical with neocuproine as regards analytical selectivity. Besides copper, titanium(III) is the only metal ion which gives a colour reaction with the reagent. However, the coloured titanium(III) complex is formed only at lower pH and hence it does not interfere with the determination of copper. The copper complex of the reagent can be extracted quantitatively with isopentyl alcohol usually as a perchlorate ion pair.
2. Neocuproine is a phenanthroline based metal ion chelating agent.

Definition

ChEBI: A member of the class of phenanthrolines that is 1,10-phenanthroline bearing two methyl substituents at positions 2 and 9.

Purification Methods

Purifiy it as the hemihydrate by crystallisation from water and as the anhydrous base from *benzene. [Beilstein 23/8 V 527.]

InChI:InChI=1/C14H12N2/c1-9-3-5-11-7-8-12-6-4-10(2)16-14(12)13(11)15-9/h3-8H,1-2H3

Synthetic route

2,3-diaminobenzene-1,4-dicarbaldehyde + acetone (67-64-1) → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
With potassium hydroxide In ethanol at 80℃; for 8h; Schlenk technique;	79%

2,3-dinitrobenzene-1,4-dicarbaldehyde + acetone (67-64-1) → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
With potassium hydroxide In ethanol for 8h; Sealed tube; Reflux;	64%

C14H12Br2N2 (942267-04-1) → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
With copper In 1-methyl-pyrrolidin-2-one for 30h; Ullmann coupling; Heating;	59%

2-methyl-8-aminoquinoline (18978-78-4) + acetaldehyde (75-07-0) + ethyl vinyl ether (109-92-2) → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
Stage #1: 2-methyl-8-aminoquinoline; acetaldehyde; ethyl vinyl ether In 2,2,2-trifluoroethanol at 30℃; Diels-Alder reaction; Stage #2: With hydrogenchloride; oxygen In water; acetonitrile under 760.051 Torr; for 16h;	42%

(E)-1,2-bis-(4-methyl-3-pyridyl)ethene → 2.9-dimethyl-1,10-phenanthroline (484-11-7) + 2,9-dimethyl-3,8-diazaphenanthrene + 2,9-dimethyl-1,8-diazaphenanthrene

Conditions	Yield
In cyclohexane for 48h; Irradiation;	A n/a B 30% C n/a

2-methyl-8-aminoquinoline (18978-78-4) + 1,1-diacetoxy-but-2-ene (78267-54-6, 5860-35-5) → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
With arsenic(V) oxide; sulfuric acid

1,10-Phenanthroline (66-71-7) + methyllithium (917-54-4) → 2-methyl-1,10-phenanthroline (3002-77-5) + 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
With manganese(IV) oxide; water Multistep reaction. Title compound not separated from byproducts;
With potassium permanganate 1.) ether/THF, 2 h, 0-10 deg C, 2 eq. MeLi; 2.) acetone; Yield given. Multistep reaction. Yields of byproduct given;

bis(2,9-dimethyl-1,10-phenathroline) copper(I) (21710-12-3) + ((C2H4O)2C6H4)NC5H2C2H2C5H2N(C6H4(C2H4O)2)OC2H4O (90030-13-0) → 2.9-dimethyl-1,10-phenanthroline (484-11-7) + Cu(C34H34N2O6)2(1+) (88503-31-5)

Conditions	Yield
In not given large excess of Cu(dmp)2(1+), than the equilibrium is totally shifted to the right; visible spectra of reaction solution;

bis(2,2'-dipyridyl)-2,9-dimethyl-o-phenantrolineruthenium(II) hexafluorophosphate → [2,2]bipyridinyl (366-18-7) + 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
for 6h; Irradiation;

2,3-dinitro-p-xylene (711-41-1) → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
Multi-step reaction with 4 steps 1: N,N-dimethyl-formamide / 140 °C / Inert atmosphere 2: sodium periodate / water; tetrahydrofuran / 24 h / 0 °C 3: iron; hydrogenchloride / ethanol; water; ethyl acetate / 3 h / Reflux 4: potassium hydroxide / ethanol / 8 h / 80 °C / Schlenk technique View Scheme

(1E,1'E)-2,2'-(2,3-dinitro-1,4-phenylene)bis(N,N-dimethylethen-1-amine) (113397-69-6) → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: sodium periodate / water; tetrahydrofuran / 24 h / 0 °C 2: iron; hydrogenchloride / ethanol; water; ethyl acetate / 3 h / Reflux 3: potassium hydroxide / ethanol / 8 h / 80 °C / Schlenk technique View Scheme
Multi-step reaction with 2 steps 1: sodium periodate / tetrahydrofuran; water / 24 h / 0 °C 2: potassium hydroxide / ethanol / 8 h / Sealed tube; Reflux View Scheme

2,3-dinitrobenzene-1,4-dicarbaldehyde → 2.9-dimethyl-1,10-phenanthroline (484-11-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: iron; hydrogenchloride / ethanol; water; ethyl acetate / 3 h / Reflux 2: potassium hydroxide / ethanol / 8 h / 80 °C / Schlenk technique View Scheme

2.9-dimethyl-1,10-phenanthroline (484-11-7) → 2,9-dimethyl-1,10-phenanthroline N-oxide (255047-70-2)

Conditions	Yield
With dihydrogen peroxide; acetic acid In water for 3.5h; Oxidation; Heating;	100%
With dihydrogen peroxide; acetic acid at 65℃; for 4.5h;	68%

2.9-dimethyl-1,10-phenanthroline (484-11-7) + (bicyclo[2.2.1]hepta-2,5-diene)tetracarbonylmolybdenum(0) (12146-37-1, 124717-04-0) → molybdenum(0) tetracarbonyl(2,9-dimethyl-1,10-phenanthroline) (23301-98-6) + bicyclo[2.2.1]hepta-2,5-diene (121-46-0)

Conditions	Yield
In tetrahydrofuran reaction in a calorimeter under argon;	A 100% B n/a

2.9-dimethyl-1,10-phenanthroline (484-11-7) + copper n-butyrate (50671-60-8) → (neocuproine)2CuO2CCH2CH2CH3

Conditions	Yield
In benzene inert atmosphere; stirring for 6 d (room temp.) (pptn.); filtering off, washing with Et2O, drying (vac.); elem. anal.;	99.7%

2.9-dimethyl-1,10-phenanthroline (484-11-7) → 2,9-Bis(trichloromethyl)-1,10-phenanthroline (78831-41-1)

Conditions	Yield
With N-chloro-succinimide; dibenzoyl peroxide In chloroform for 72h; Reflux;	99%
With N-chloro-succinimide; triphenylphosphine In tetrachloromethane at 80 - 85℃; for 7h;	95%
With N-chloro-succinimide In chloroform for 6h; Heating;	90%

2.9-dimethyl-1,10-phenanthroline (484-11-7) + [Ag(N3)(P(C6H5)3)2]2 → Ag(I)(N3)(PPh3)(2,9-dimethyl-1,10-phenanthroline) complex (385825-49-0)

Conditions	Yield
In diethyl ether under N2; Schlenk techniques; soln./suspn. of 2,9-dimethyl-1,10-phenanthroline added to soln. of Ag(N3)(PPh3)2 at 273 K; stirred overnight at room temp.; ligand-to-metal molar ratio of 4:1; filtered off; ppt. washed with diethyl ether-ethanol (3:1); recrystd. from acetonitrile-diethyl ether (1:1); elem.anal.;	99%

copper(II) nitrate trihydrate + 2.9-dimethyl-1,10-phenanthroline (484-11-7) + sodium dicyanamide (1934-75-4) → [Cu2(2,9-dimethyl-1,10-phenanthroline)2(dicyanamide)4] (758716-17-5)

Conditions	Yield
In water addn. of aq. soln. of NaN(CN)2 to aq. soln. of Cu(NO3)2*3H2O and 2,9-dimethyl-1,10-phenanthroline; crystn., elem. anal.;	99%

tetrakis(acetonitrile)copper(I)tetrafluoroborate + 2.9-dimethyl-1,10-phenanthroline (484-11-7) + tetramethylammonium picrate (733-60-8) → bis(2,9-dimethyl-1,10-phenanthroline)copper(I) picrate (87045-32-7)

Conditions	Yield
In water; acetonitrile Cu complex and stoich. amt. of ligand dissolved in MeCN-H2O; picrate (10% excess) added; refluxed for 2 h; crystd. by slow evapn.;	99%

Upstream product

• 942267-04-1 C₁₄H₁₂Br₂N₂ 
• 57709-62-3 1,10-phenanthroline-2,9-dicarboxaldehyde 
• 67-64-1 acetone 
• 113397-69-6 (1E,1'E)-2,2'-(2,3-dinitro-1,4-phenylene)bis(N,N-dimethylethen-1-amine) 
• 711-41-1 2,3-dinitro-p-xylene 
• 18978-78-4 2-methyl-8-aminoquinoline 
• 75-07-0 acetaldehyde 
• 109-92-2 ethyl vinyl ether 
• 21710-12-3 bis(2,9-dimethyl-1,10-phenathroline) copper(I) 
• 90030-13-0 ((C₂H₄O)2C₆H₄)NC₅H₂C₂H₂C₅H₂N(C₆H₄(C₂H₄O)2)OC₂H₄O 
• 66-71-7 1,10-Phenanthroline 
• 917-54-4 methyllithium 
• 78267-54-6 1,1-diacetoxy-but-2-ene 

Downstream Products

• 691413-56-6 2,9-diphenylethyl-1,10-phenanthroline 
• 691413-57-7 2,9-bis-{2-[4-(tert-butyl-dimethyl-silanyloxy)-phenyl]-ethyl}-[1,10]phenanthroline 
• 177190-82-8 {Cu(2,9-dimethyl-1,10-phenanthroline)(P(C₆H₄OMe-p)3)2}ClO₄ 
• 119769-35-6 PtClEt(2,9-Me₂-1,10-phenanthroline)(C₂H₄) 
• 5259-72-3 cyclo-octa-1,5-diene 
• 119744-12-6 PtClMe(2,9-Me₂-1,10-phenanthroline)((E)-MeCH=CHMe) 
• 75-18-3 dimethylsulfide 
• 1266331-37-6 N,N'-bis(phenyl-4-ethoxypiperidine)-1,10-phenanthroline-2,9-carboxamide 
• 1266331-38-7 N,N'-bis(phenyl-4-ethoxypyrrole)-1,10-phenanthroline-2,9-carboxamide 
• 1301127-06-9 N,N'-bis(phenyl-4-ethoxymorpholine)-1,10-phenanthroline-2,9-carboxamide 
• 1301127-07-0 N,N'-bis(phenyl-4-ethoxydimethylamino)-1,10-phenanthroline-2,9-carboxamide 
• 1266331-36-5 N,N'-bis(4-aminophenol)-1,10-phenanthroline-2,9-carboxamide 
• 1402551-71-6 [(2,9-dimethyl-1,10-phenanthroline)Cu(μ-p-thiocresol(-1H))]2 
• 97567-29-8 2,9-dimethyl-1,10-phenanthroline-bis(triphenyl)phosphine copper(I)tetrafluoroborate 

Relevant articles and documents

Viologen embedded polyaromatic hydrocarbons (VPAH2+): Synthesis, computational, photophysical, and electrochemical characterizations of 3,8-diazaphenanthrenyl viologens

Several new dicationic viologen sensitizers are synthesized and characterized both photo- and electro-chemically. Benzo-annulation of methyl viologen increases its fluorescence lifetime by a factor of 6.6. Similar lifetime increases were observed for methylated derivatives, that have the added advantage of enhanced solubilities. These electron transfer sensitizers can oxidize organic substrates with oxidation potentials of approximately 2.4 eV and lower.

Sequential multiple-target chemosensor: Co2+, Cu2+, PPi, and HSˉ discrimination by a bis(half-salamo)-type probe

A bis(half-salamo)-type chemosensor LPBHS based on phenanthroline, which can identify multiple targets continuously, was synthesized. The chemosensor LPBHS utilizes the N3O cavities to combine with metal cations, and further identify the anions after the complexes have been formed. The chemosensor LPBHS has an O-phenanthroline unit with excellent luminescence, so that the strong fluorescence of the chemosensor LPBHS can be observed under 365 nm UV light. The quenching of luminescence occurs after the introduction of Cu2+ and Co2+ into the chemosensor LPBHS, which can be identified in natural light by observing the change in color of the solution with the naked eye. The LPBHS-Cu2+ complex further recognizes HSˉ and PPi (pyrophosphoric acid), and strong luminescence are also observed under UV light after the addition of HSˉ and PPi to LPBHS-Cu2+. HSˉ and PPi can also be identified by the change in color of the solution under natural light with the naked eye. Using the strong fluorescence emission of LPBHS, a test strip was developed to detect Cu2+ and Co2+ rapidly, and the quenching of fluorescence was clearly observed under UV light. HSˉ and PPi can be further identified by the phenomenon of fluorescence recovery after Cu2+ detection on the test strip.

Preparation of a New Friedl?nder Synthon, 2,3-Diaminobenzene-1,4-dicarbaldehyde, and Its Application towards Synthesis of 1,10-Phenanthrolines and Related Cyclophane

A new Friedl?nder synthon, 2,3-diaminobenzene-1,4-dicarbaldehyde, was prepared from p-xylene in 4 steps, of which the Friedl?nder reaction with acetaldehyde and acetone in a Schulenk bottle afforded 1,10-phenathroline and neocuprine in 44% and 82% yield, respectively. The scope of the Friedl?nder reactions of 2,3-diaminobenzene-1,4-dicarbaldehyde, including the synthesis of hexaazacyclic cyclophane with 1,10-phenanthroline and pyridine units, was described.