Question

name these organic compounds: structure image of a benzene ring with a br (bromine) substituent and a f (fluorine) substituent attached to the ring

Explanation:

Step1: Identify the parent structure

The parent structure is a benzene ring (aromatic ring).

Step2: Identify the substituents

The substituents are bromine (Br) and fluorine (F).

Step3: Determine the positions of substituents

In a benzene ring with two substituents, we use the numbering to give the lowest possible numbers to the substituents. Here, the bromine is at position 1 and fluorine at position 3 (or we can use ortho, meta, para but for two substituents with different atoms, numbering is better, but also, when using the prefixes, bromo and fluoro, and since F and Br are halogens, we order them by alphabetical order of their prefixes: fluoro comes before bromo? Wait, no, the alphabetical order of the substituent names: "bromo" and "fluoro". The first letter: B vs F. F comes before B? Wait, no, alphabetical order: bromo (B) and fluoro (F). Wait, no, F is after B? Wait, B (bromo) and F (fluoro). So alphabetically, bromo comes before fluoro? Wait, no, the letter B is before F, so bromo is before fluoro? Wait, no, the IUPAC naming for disubstituted benzenes: when two substituents are present, we number the ring to give the lowest possible numbers, and also, when the substituents are different, we order them alphabetically by their prefixes. Wait, the prefixes are "bromo-" (for Br) and "fluoro-" (for F). The alphabetical order of the prefixes: "bromo" starts with B, "fluoro" starts with F. So B comes before F, so bromo should be before fluoro? Wait, no, wait, the correct alphabetical order for the substituent groups: the first letter of the substituent name (excluding the "o" at the end for halogen prefixes). So "bromo" (Br) and "fluoro" (F). So B (bromo) comes before F (fluoro)? Wait, no, B is the 2nd letter, F is the 6th. So B comes before F. Wait, but in the structure, the bromine is at the top (let's assume position 1) and fluorine at position 3 (since it's a benzene ring, positions are 1,2,3,4,5,6). Wait, actually, in the structure, the bromine is at position 1, and fluorine is at position 3 (meta to bromine? Wait, no, the fluorine is adjacent to the bromine? Wait, no, the benzene ring has six carbons. Let's number the carbon with Br as 1, then the adjacent carbons are 2 and 6, then 3 and 5, then 4. Wait, the fluorine is attached to the carbon adjacent to the Br? Wait, no, looking at the structure: the Br is at the top (carbon 1), and F is at the carbon that is two positions away from Br? Wait, no, the structure shows Br at the top (carbon 1), and F at the carbon that is, let's see, the benzene ring: carbon 1 (Br), carbon 2 (next), carbon 3 (F), carbon 4, carbon 5, carbon 6. So the positions are 1 (Br) and 3 (F). So the substituents are at 1 and 3 positions. Now, the prefixes: bromo (for Br) and fluoro (for F). Now, alphabetical order: "bromo" and "fluoro". The first letter: B (bromo) and F (fluoro). So B comes before F, so we should list bromo first? Wait, no, wait, the IUPAC rule is that when ordering substituents, we use the alphabetical order of the substituent names (excluding the "o" at the end for halogen prefixes, but actually, the full prefix: "bromo-" and "fluoro-". So "bromo" starts with B, "fluoro" with F. So B is before F, so bromo comes before fluoro. Wait, but wait, maybe I got it reversed. Let me check: the alphabetical order of the substituent groups: for example, chloro (Cl), bromo (Br), fluoro (F). The order is fluoro, bromo, chloro? No, wait, the alphabetical order is based on the first letter of the substituent name. So F (fluoro) comes before B (bromo)? Wait, no, F is the 6th letter, B is the 2nd. So B comes before F. So bromo is before fluoro. Wait, this is confusing. Wait, let's check the IUPAC nomenclature for haloarenes. The correct order is based on the alphabetical order of the halogen names: bromine (Br) and fluorine (F). The names of the halogens: bromine, fluorine. Alphabetically, bromine comes before fluorine? No, fluorine (F) comes before bromine (Br) in the alphabet? Wait, F is the 6th letter, B is the 2nd. So B comes before F. So bromine is before fluorine. Wait, no, the alphabetical order is from A to Z: B (bromine) comes before F (fluorine). So when naming, the substituent with the earlier alphabetical name comes first. So bromo (from bromine) comes before fluoro (from fluorine). Wait, but let's take an example: 1-bromo-3-fluorobenzene. Alternatively, if the positions are 1 and 3, and the substituents are Br and F. Wait, but maybe the structure is 1-bromo-3-fluorobenzene, or is it 3-bromo-1-fluorobenzene? No, because we number to give the lowest possible number to the first substituent in alphabetical order. Wait, no, the rule is: when numbering the ring, we assign the lowest possible number to the substituent that comes first alphabetically. Wait, that's the key. So first, determine the alphabetical order of the substituents: fluoro (F) and bromo (Br). Wait, F (fluoro) starts with F, B (bromo) starts with B. So B comes before F, so bromo is first. So we number the ring so that the bromo group gets the lowest possible number, then the fluoro group. Wait, but in the structure, the bromo is at the top (let's say position 1), and fluoro is at position 3. So the name would be 1-bromo-3-fluorobenzene. Alternatively, using the ortho, meta, para notation, but since they are not adjacent (ortho) or opposite (para), they are meta (1,3 positions). So another way is m-bromo-fluorobenzene, but the IUPAC preferred is using numbers. Wait, but let's confirm: the correct IUPAC name for a benzene ring with Br at position 1 and F at position 3 is 1-bromo-3-fluorobenzene. Alternatively, since the two substituents are bromine and fluorine, and we order them alphabetically: bromo (B) and fluoro (F), so bromo comes first. So the numbering is such that bromo is at 1, fluoro at 3. So the name is 1-bromo-3-fluorobenzene.

Answer:

1 - bromo - 3 - fluorobenzene