Narrated Ibn Abbas:
Allah's Messenger (Sallallahu Alaihi Wasallam) cursed those men who are in the similitude (assume the manners) of women and those women who are in the similitude (assume the manners) of men.
(Sahih Al-Bukhari, Volume 7, Book 72, Hadith 773)
It is forbidden for a man to assume the manners the woman (manners is the movement, soft speech, adornments, clothing and other things that makes a woman). The same applies to a woman who assume a man's manner.
It is also forbidden to imitate a kafir (disbeliever).
Men are not allowed to wear necklaces (chains) as it commonly what a woman wear (of any kind).
Wearing a necklace with the name Allah on it is copying a kafir (disbeliever). Kafir (disbeliever) wear necklaces with a cross or star of David.
You said that you are not trying to
imitate woman but in fact wearing a
necklace (chain) by a Muslim man for whatever
reason is considered imitating a
Why would you want to wear a necklace with Allah on it? I believe you are trying to show off (Riyaa) to other people that look I am a good Muslim. Doing showing off (Riyaa) is forbidden in Islam. If you want to seek Allah's pleasures and go to Jannah (Heaven) then be preoccupied in your worship to Allah and not go after such useless pursuit of a kafir (disbeliever). It is Shaytan (Devil) who is making you think that by wearing a necklace (whether it be a chain of any kind) is allowed in Islam when in fact it is not. Please try to seek refuge in Allah from Shaytan unless it is your desire to go to Jahannam (Hell-Fire) through useless pursuit of copying a kafir (disbeliever) and the imitation of woman.
Guide us to the straight path -- Surah Al-Fatihah, Verse 6, Qur'an