(ii) a combination of an optionally-substituted phenylene group (-Ph-), an optionally-substituted alkylene group having 1 to 24 carbon atoms, and at least one selected from the group consisting of an amide bond (—NH—CO— or —CO—NH—), an ether bond (—O—), a thioether bond (—S—), a urethane bond (—NH—CO—O— or —O—CO—NH—), an imino group (—NH—), a carbonyl group (—CO—), and a urea bond (—NH—CO—NH—).

L in the aforementioned (i) or (ii) may have two or more of each of the “at least one selected from the group consisting of an amide bond (—NH—CO— or —CO—NH—), an ether bond (—O—), a thioether bond (—S—), a urethane bond (—NH—CO—O— or —O—CO—NH—), an imino group (—NH—), a carbonyl group (—CO—), and a urea bond (—NH—CO—NH—)”, the “optionally-substituted alkylene group having 1 to 24 carbon atoms”, and the “optionally-substituted phenylene group (-Ph-)”. For example, L in the aforementioned (i) may have a biphenylene structure (-Ph-Ph-) in which two “optionally-substituted phenylene groups (-Ph-)” are connected.

L is preferably a divalent spacer represented by the formula (2):

[Image Omitted]

(in the formula (2),

- m1 is 0 or 1,
- m2 is an integer of 1 to 3,
- w is 1 or 2,
- R², R³, R⁴, and R⁵are each independently a hydrogen atom or a substituent,
- * is a bonding point with P¹, and
- ** is a bonding point with N).

In the formula (2), m1 and m2 are each the number of repeats of the methylene unit. m1 is 0 or 1, preferably 0. That m1 is 0 here means that —(CH₂)_m1— is a single bond. m2 is an integer of 1 to 3, preferably 3.

In the formula (2), w is the number of repeats of the optionally-substituted phenylene unit. w is 1 or 2, preferably 1.

In the formula (2), m1 is preferably 0, and w is preferably 1.

In the formula (2), R²to R⁵are each independently a hydrogen atom or a substituent.

When w is 2, R²in the number of two may be the same or different, R³in the number of two may be the same or different, R⁴in the number of two may be the same or different, and R⁵in the number of two may be the same or different.

Examples of the substituent for R²to R⁵include halogen atom, alkyl group having 1 to 4 carbon atoms, halogenated alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms, halogenated alkoxy group having 1 to 4 carbon atoms, acyl group having 2 to 5 carbon atoms, alkoxycarbonyl group having 2 to 5 carbon atoms, carbamoyl group having 2 to 5 carbon atoms, acyloxy group having 2 to 5 carbon atoms, acylamino group having 2 to 5 carbon atoms, alkoxycarbonylamino group having 2 to 5 carbon atoms, alkylsulfanyl group having 1 to 4 carbon atoms, alkylsulfonyl group having 1 to 4 carbon atoms, arylsulfonyl group having 6 to 10 carbon atoms, nitro group, trifluoromethyl group, a cyano group, and the like.

R²to R⁵are preferably each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a nitro group, more preferably a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group, further preferably a hydrogen atom, a methoxy group, or a nitro group.

In the formula (2),

- m1 is preferably 0 or 1, m2 is preferably an integer of 1 to 3, w is preferably 1 or 2, and R²to R⁵are preferably each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is more preferably 0 or 1, m2 is more preferably an integer of 1 to 3, w is more preferably 1 or 2, and R²to R⁵are more preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is further preferably 0 or 1, m2 is further preferably an integer of 1 to 3, w is further preferably 1 or 2, and R²to R⁵are further preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is particularly preferably 0, m2 is particularly preferably 3, w is particularly preferably 1, and R²to R⁵are particularly preferably each independently a hydrogen atom, a methoxy group, or a nitro group.

As L represented by the formula (2), a divalent spacer represented by the formula (2a):

[Image Omitted]

(in the formula (2a), the symbols are as defined above), a divalent spacer represented by the formula (2b):

[Image Omitted]

(in the formula (2b), the symbols are as defined above), or a divalent spacer represented by the formula (2c):

[Image Omitted]

(in the formula (2c), R^2ato R^5aand R^2bto R^5bare each independently a hydrogen atom or a substituent, and other symbols are as defined above) is preferred. The substituents for R^2ato R^5aand R^2bto R^5bare the same as those for the aforementioned R²to R⁵.

In the formula (2a),

- m1 is preferably 0 or 1, m2 is preferably an integer of 1 to 3, and R²to R⁵are preferably each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is more preferably 0 or 1, m2 is more preferably an integer of 1 to 3, and R²to R⁵are more preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is further preferably 0 or 1, m2 is further preferably an integer of 1 to 3, and R²to R⁵are further preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is particularly preferably 0, m2 is particularly preferably an integer of 1 to 3, and R²to R⁵are particularly preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is most preferably 0, m2 is most preferably 3, R²is most preferably a hydrogen atom or a methoxy group, and R³to R⁵are each most preferably a hydrogen atom.

In the formula (2b),

- m1 is preferably 0 or 1, m2 is preferably an integer of 1 to 3, and R²to R⁵are preferably each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is more preferably 0 or 1, m2 is more preferably an integer of 1 to 3, and R²to R⁵are more preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is further preferably 0 or 1, m2 is further preferably an integer of 1 to 3, and R²to R⁵are further preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is particularly preferably 0, m2 is particularly preferably an integer of 1 to 3, and R²to R⁵are particularly preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is most preferably 0, m2 is most preferably 3, and R²and R⁴are most preferably each independently a hydrogen atom, a methoxy group, or a nitro group, and R³and R⁵are each most preferably a hydrogen atom.

In the formula (2c),

- m1 is preferably 0 or 1, m2 is preferably an integer of 1 to 3, and R^2ato R^5aand R^2bto R^5bare preferably each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is more preferably 0 or 1, m2 is more preferably an integer of 1 to 3, and R^2ato R^5aand R^2bto R^5bare more preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is further preferably 0 or 1, m2 is further preferably an integer of 1 to 3, and R^2ato R^5aand R^2bto R^5bare further preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is particularly preferably 0, m2 is particularly preferably an integer of 1 to 3, and R^2ato R^5aand R^2bto R^5bare particularly preferably each independently a hydrogen atom, an alkoxy group having 1 to 4 carbon atoms, or a nitro group,
- m1 is most preferably 0, m2 is most preferably 3, and R^2ato R^5aand R^2bto R^5bare each most preferably a hydrogen atom.

Preferred examples of the polyoxyethylene derivative (1) of the present invention include the following polyoxyethylene derivative (1-1) to polyoxyethylene derivative (1-6).