9 Fluorenone Acid Or Base

9-Fluorenone: Acid or Base? Understanding its Reactivity

Fluorenone, particularly its 9-substituted derivative, is a fascinating molecule that often presents a challenge for those new to organic chemistry. Its seemingly simple structure belies a nuanced reactivity profile, leading to questions about its acidic or basic nature. While not a strong acid or base in the conventional sense, 9-fluorenone exhibits specific properties that influence its behavior in different chemical environments. This article aims to clarify its reactivity, exploring its potential to act as both an acid and a base under specific conditions, and providing practical insights into its applications.

Understanding the Structure and Electronic Properties of 9-Fluorenone

9-Fluorenone is a bicyclic aromatic ketone characterized by a carbonyl group (C=O) at the 9-position bridging two benzene rings. This carbonyl group plays a crucial role in determining the molecule's reactivity. The carbonyl oxygen possesses a significant partial negative charge due to the electronegativity difference between carbon and oxygen, making it susceptible to electrophilic attack. Conversely, the carbon atom of the carbonyl group carries a partial positive charge, making it susceptible to nucleophilic attack. Furthermore, the aromatic rings contribute to the molecule's overall electron distribution, influencing its interactions with other molecules. The planarity of the fluorenone structure contributes to efficient delocalization of electrons, impacting its stability and reactivity.

9-Fluorenone as a Weak Acid: Enolisation and Keto-Enol Tautomerism

While not a strong acid like carboxylic acids, 9-fluorenone can exhibit weak acidic properties through its keto-enol tautomerism. The alpha-hydrogens (hydrogens attached to the carbon atom adjacent to the carbonyl group) can be abstracted by a strong base, leading to the formation of an enolate ion. This process is significantly less facile than in, say, a carboxylic acid due to the resonance stabilization of the carbonyl group in the keto form. However, under strongly basic conditions, such as treatment with a Grignard reagent or a strong base like sodium amide (NaNH2), the enolate can be formed. This enolate ion can then participate in various reactions such as alkylation or acylation.

A real-world example of this weak acidity is seen in the aldol condensation reaction. While less efficient than reactions with aldehydes, 9-fluorenone can, under specific conditions (strong base and suitable aldehyde), undergo aldol condensation, producing a β-hydroxy ketone. This demonstrates the molecule's capacity to act as a weak acid, albeit under rather specific and forcing conditions.

9-Fluorenone as a Weak Base: Coordination Chemistry

9-Fluorenone can also display weak basic characteristics, although this is not as pronounced as its weak acidic properties. The carbonyl oxygen, despite its partial negative charge, can act as a Lewis base, donating a lone pair of electrons to a Lewis acid. This is most commonly observed in coordination chemistry where 9-fluorenone can complex with metal ions. The oxygen atom can coordinate to a metal center, forming a metal-ligand complex. The strength of this interaction depends heavily on the nature of the metal ion and its coordination environment. For instance, transition metal ions with a high charge density are more likely to form stable complexes with 9-fluorenone.

This basic character finds application in areas like catalysis where 9-fluorenone can act as a ligand, influencing the reactivity of a metal catalyst. The specific nature of the catalytic reaction will be greatly influenced by the choice of metal and the reaction conditions.

Applications of 9-Fluorenone's Reactivity

The understanding of 9-fluorenone's dual reactivity is crucial for its practical applications. Its use as a precursor in organic synthesis is widespread, leveraging its ability to undergo both electrophilic and nucleophilic reactions. Furthermore, its weak acidic properties are exploited in specific aldol condensation reactions, while its ability to act as a Lewis base finds applications in coordination chemistry and catalysis. The photophysical properties of 9-fluorenone also contribute to its use in fluorescence microscopy and other optical applications.

Conclusion

9-fluorenone, despite its seemingly simple structure, exhibits a rich and nuanced reactivity profile. Its behavior is significantly influenced by the presence of the carbonyl group and the aromatic rings. While not a strong acid or base, it demonstrates weak acidic properties through enolisation and weak basic properties through Lewis base coordination. Understanding these subtle nuances is essential for its effective application in organic synthesis, coordination chemistry, and catalysis.

FAQs

1. Is 9-fluorenone more acidic or basic? 9-Fluorenone displays more pronounced weak acidic properties than weak basic properties under typical reaction conditions. However, the "strength" of both characteristics is relatively weak compared to conventional acids and bases.

2. What are the common solvents used with 9-fluorenone? The choice of solvent depends on the specific reaction. Common solvents include aprotic solvents like THF, DMF, or DMSO for reactions requiring strong bases, and less polar solvents like dichloromethane or toluene for reactions involving weaker reagents.

3. How does the substitution pattern on the fluorene rings affect the acidity/basicity? Electron-withdrawing groups on the aromatic rings will enhance the acidity of 9-fluorenone by stabilizing the enolate ion. Electron-donating groups will have the opposite effect.

4. Can 9-fluorenone be used in pharmaceutical synthesis? Yes, 9-fluorenone and its derivatives have been used as building blocks in the synthesis of various pharmaceuticals, often leveraged in creating bioactive molecules with specific functionalities.

5. What safety precautions should be taken when handling 9-fluorenone? Standard laboratory safety precautions should always be followed. 9-Fluorenone is an irritant, and appropriate personal protective equipment (PPE), including gloves and eye protection, should be used. Proper ventilation should also be ensured.

Search Results:

[Ochem 1] Double check my extraction procedure? : r/chemhelp 3 Oct 2016 · Now, using pKa values I know benzoic acid is most acidic (~5), then the benzocaine (~40 for the amine group), then the 9-Fluorene (~43 for the aromatic hydrogens), correct? …

9-Fluorenone | C13H8O | CID 10241 - PubChem 9-Fluorenone | C13H8O | CID 10241 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety/hazards/toxicity …

Solvent Extraction Experiment Using Liquid-Liquid Extraction 18 May 2020 · The purpose of this experiment is to use liquid-liquid extraction, a form of solvent extraction, to separate a mixture of an organic acid (benzoic acid), organic base (ethyl-4 …

What is the pKa of 9-Fluorenone? - Answers 20 May 2024 · The pKa of 9-Fluorenone is typically around 9.4. This means that at a pH below 9.4, it will predominantly exist in its protonated form, while at pH above 9.4, it will be mostly in …

Solved 6. For this experiment, you will be using | Chegg.com 6. For this experiment, you will be using 9-fluorenone and benzoic acid. a. Draw the bond-line structures. b. Based on the bond-line structures, which of these is an organic acid? - Benzoic …

Is 9 Fluorenone an acid or base? - Knowledge - Xiaoyi JinJing … 6 Dec 2019 · Ethyl 4-aminobenzoate is soluble in acid, forming 4-ethoxycarbonyanilinium ion. 9-fluorenone is not acidic or basic in water, and in insoluble in aqueous solutions. The benzoic …

Lab 4 acid and base extraction (pdf) - CliffsNotes 31 Jan 2025 · To separate benzoic acid from 9- Flourenone, the addition of 3M NaOH does the job. The extraction of benzoic acid will result in crystallization with the addition of 6M HCl. The …

Solved Answer #1 using the compounds listed in the | Chegg.com To start, consider the acidic nature of benzoic acid and write its reaction with sodium hydroxide (N a O H) to form sodium benzoate and water. 9-flourenone does not react with NaOH/HCl as it …

Orgo 1 Lab report 3 - Experiment 4C: Solvent Extraction II: Acid-Base ... Experiment 4C: Solvent Extraction II: Acid-Base Extraction Using a Mixture of 9-Flurorenone and Ethyl 4-Aminobenzoate Objective: This experiment aimed to continue performing the solvent …

9-Fluorenone | 486-25-9 - ChemicalBook 27 Jan 2025 · 9-Fluorenone (CAS 486-25-9) information, including chemical properties, structure, melting point, boiling point, density, formula, molecular weight, uses, prices, suppliers, SDS …

Chromproc - lab report - CHEM 2229 EXP 1: Oxidation of 9 Objective: In this experiment you will learn how to perform an oxidation reaction by oxidizing an alcohol (9- hydroxyfluorene) to a ketone (9-fluorenone) using sodium hypochlorite in an acidic …

Lab 4 acid and base extraction - Experiment 3: Acid and Base To separate benzoic acid from 9- Flourenone, the addition of 3M NaOH does the job. The extraction of benzoic acid will result in crystallization with the addition of 6M HCl. The …

Solved Pre-lab Questions: Using the Acid-Base Properties of - Chegg For this experiment, you will be using 9-fluorenone and benzoic acid. Draw the bond-line structures. Based on the bond-line structures, which of these is an organic acid? Explain what …

Group 13 trihalide complexes of 9-fluorenone: a comparison of … 20 Jan 2003 · In this regard, the Keq at 298 K and Δ G would appear to be the best measures of the ability of a Lewis acid to bind a specific Lewis base, while the Δ λmax for the 9- fluorenone …

Fluorenone - Wikipedia Fluorenone is an organic compound with the chemical formula (C6H4)2CO, a ketone with fluorene moiety. It is bright fluorescent yellow solid. [2] It is synthesised by aerobic oxidation of fluorene: …

Structure of 9-Fluorenone (C13H8O) - Mol-Instincts 9-Fluorenone contains total 24 bond (s); 16 non-H bond (s), 13 multiple bond (s), 1 double bond (s), 12 aromatic bond (s), 1 five-membered ring (s), 2 six-membered ring (s), 2 nine-membered …

Module 3 - Experiment 4C: The Separation of a Two Compound … require the separation of compounds that are either acid, benzoic acid, and neutral, 9-fluorenone, or basic, ethyl 4-aminobenzoate, and neutral,9-fluorenone, in a setting like research or …

231L Extraction final (pdf) - CliffsNotes 26 Apr 2024 · For this experiment, you will be using 9-fluorenone and benzoic acid. a. (10 pts) Draw the bond-line structures. b. (4 pts) Based on the bond-line structures, which of these is …

Lab Report #7 copy - no other data needed - Lab report # The Lastly, isolating 9-fluorenone, which is neither acid or base compound, done assuming that the benzoic acid and benzocaine are completely extracted. Based on the overall characteristics, …

Solvent Extraction Techniques for Compound Separation: Acid, 28 Feb 2024 · Chemistry document from Temple University, 5 pages, Experiment 4C: The Separation of a Two Compound Mixture of a Neutral (9-Fluorenone) and an Acid (Benzoic …

9 Fluorenone Acid Or Base