JP4748670B2 - Magnetic recording element - Google Patents

Description

  The present invention relates to a magnetic recording element, and more particularly to a magnetic recording element using a transition metal complex in which thermally induced spin transition forms a cross hysteresis loop.

In an octahedral ligand field, the central metal ion has 4 to 7 d electrons, and the high spin state or low spin state depends on whether the energy of the ligand field is smaller or larger than the electron pair formation energy. It is common to take an electronic arrangement of states.
If these parameters are approximately the same size, conversion between spin states may occur due to the influence of changes in temperature, pressure, or external conditions such as light irradiation. Called “transition”, “spin crossing”, or “spin crossover”.

The spin transition phenomenon is accompanied by the magnetic, absorption spectrum, refractive index, electricity, vibration and structural changes of the compound. Utilizing these characteristics, development to sensors, data storage, display, signal processing and the like is expected.
The present inventors have so far found that a Co complex having a terpyridine ligand has a magnetic hysteresis and has a gradual change in molar magnetic susceptibility. No transition has been found (see Non-Patent Document 1, Non-Patent Document 2, and Non-Patent Document 3).

“Inorg. Chem.” (USA), 2004, Vol. 43, p. 4124-4126 “Inorg. Chem.” (USA), 2005, vol. 44, p. 7295-7297 "Angew. Chem. Int. Ed.", (Germany), 2005, vol. 44, p. 4899-4903

  The present invention has been made in view of such circumstances, and an object thereof is to provide a magnetic recording element using a transition metal complex in which thermally induced spin transition forms a cross hysteresis loop.

｛式中、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵、及びＲ⁶は、それぞれ独立に、水素原子、ハロゲン原子、ニトロ基、シアノ基、炭素数１〜１０のアルキル基〔このアルキル基はハロゲン原子、ヒドロキシル基、カルボキシル基、炭素数１〜３のアルコキシ基、フェニル基（このフェニル基はハロゲン原子、炭素数１〜３のアルコキシ基、又は炭素数１〜１０のアルキル基で任意に置換されていてもよい。）で任意に置換されていてもよい。〕、炭素数３〜６のシクロアルキル基、炭素数１〜６のアルコキシ基、フェニル基〔このフェニル基はハロゲン原子、炭素数１〜３のアルコキシ基、又は炭素数１〜１０のアルキル基で任意に置換されていてもよい。〕を表し、Ｍは、Ｍｎ（ＩＩ）、Ｍｎ（ＩＩＩ）、Ｆｅ（ＩＩ）、Ｆｅ（ＩＩＩ）、Ｃｏ（ＩＩ）、Ｃｏ（ＩＩＩ）、又はＮｉ（ＩＩ）を表し、Ｘは、ＣＦ₃ＳＯ₃ ^-、ＣＨ₃−Ｐｈ−ＳＯ₃ ^-、ＮＣＳ^-、ＣＮ^-、Ｃｌ^-、Ｂｒ^-、ＢＦ₄ ^-、ＢＰｈ₄ ^-、ＣｌＯ₄ ^-、又はＰＦ₆ ^-を表し、ｎは２又は３を表す。｝
２． 前記Ｍが、Ｆｅ（ＩＩ）、Ｆｅ（ＩＩＩ）、又はＣｏ（ＩＩ）である１の磁気記録素子、
３． 前記Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、及びＲ⁵が、それぞれ独立に、水素原子、塩素原子、臭素原子、メチル基、エチル基、又はノルマルプロピル基を表し、前記Ｒ⁶が、それぞれ独立に、水素原子、塩素原子、臭素原子、シアノ基、メチル基、エチル基、ノルマルプロピル基、イソプロピル基、ノルマルブチル基、イソブチル基、セカンダリーブチル基、ターシャリーブチル基、トリフルオロメチル基、ヒドロキシメチル基、ヒドロキシエチル基、カルボキシメチル基、メトキシ基、エトキシ基、ノルマルプロポキシ基、イソプロポキシ基、フェニル基、ペンタフルオロフェニル基、アニソール基、又はトリル基を表す１又は２の磁気記録素子、
４． 前記Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、及びＲ⁵が、水素原子を表し、前記Ｒ⁶が、水素原子又はメトキシ基を表し、前記Ｍが、Ｃｏ（ＩＩ）を表し、前記Ｘが、ＢＦ₄ ^-を表し、前記ｎが２である１〜３のいずれかの磁気記録素子
を提供する。
As a result of intensive studies to achieve the above object, the present inventors have found that a metal complex having terpyridine as a tridentate ligand causes a thermally induced spin transition that forms a cross-hysteresis loop. Was completed.
That is, the present invention
1. A magnetic recording element using a transition metal complex in which thermally induced spin transition forms a cross hysteresis loop, wherein the transition metal complex is represented by the formula (1):

{Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 10 carbon atoms [this The alkyl group is a halogen atom, a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 3 carbon atoms, or a phenyl group (this phenyl group is a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 10 carbon atoms). Optionally substituted)). ], A cycloalkyl group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group [this phenyl group is a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 10 carbon atoms. It may be optionally substituted. M represents Mn (II), Mn (III), Fe (II), Fe (III), Co (II), Co (III), or Ni (II), and X represents CF ₃ SO ₃ ⁻ , CH ₃ —Ph—SO ₃ ⁻ , NCS ⁻ , CN ⁻ , Cl ⁻ , Br ⁻ , BF ₄ ⁻ , BPh ₄ ⁻ , ClO ₄ ⁻ , or PF ₆ ⁻ , and n represents 2 or 3 To express. }
2. The magnetic recording element of 1, wherein M is Fe (II), Fe (III), or Co (II);
3. Wherein ^{R 1, R 2, R 3} , R 4, and R ^5, each independently, a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, an ethyl group, or n-propyl group, wherein R ⁶ is each Independently, hydrogen atom, chlorine atom, bromine atom, cyano group, methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, isobutyl group, secondary butyl group, tertiary butyl group, trifluoromethyl group, hydroxy 1 or 2 magnetic recording elements representing a methyl group, hydroxyethyl group, carboxymethyl group, methoxy group, ethoxy group, normal propoxy group, isopropoxy group, phenyl group, pentafluorophenyl group, anisole group, or tolyl group,
4). R ¹ , R ² , R ³ , R ⁴ , and R ⁵ represent a hydrogen atom, R ⁶ represents a hydrogen atom or a methoxy group, M represents Co (II), and X represents BF ₄ ⁻ , wherein n is 2 and the magnetic recording element of any one of 1 to 3 is provided.

  According to the present invention, a magnetic recording element using a metal complex in which thermally induced spin transition forms a cross hysteresis loop can be provided. Since this metal complex forms a hysteresis loop with crossing heat-induced spin transitions, it has a wider temperature range than conventional non-crossing hysteresis loop spin transition complexes. Since the property is seen, it can be used in a wide range in the application of a recording element or the like using this feature. In addition, since the spin transition is crossed, the temperature history of the magnetic material can be known by measuring the temperature dependence of the magnetic susceptibility, so that it can be applied as a thermosensor. .

Hereinafter, the present invention will be described in more detail.
The magnetic recording element according to the present invention uses a transition metal complex in which thermally induced spin transition forms a cross hysteresis loop. Here, as a transition metal complex, what is shown by the said Formula (1) is mentioned, for example.
In the formula (1), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 10 carbon atoms. [This alkyl group is a halogen atom, a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 3 carbon atoms, a phenyl group (this phenyl group is a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 10 carbon atoms. Optionally substituted with a group). ], A cycloalkyl group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group [this phenyl group is a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 10 carbon atoms. It may be optionally substituted. ] Is represented.

Specifically, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the optionally substituted alkyl group having 1 to 10 carbon atoms include methyl, ethyl, propyl, isopropyl, normal butyl, isobutyl, secondary butyl, and tertiary butyl. Group, normal pentyl group, amyl group, isoamyl group, tertiary amyl group, neopentyl group, normal hexyl group, heptyl group, octyl group, nonyl group, decyl group, trifluoromethyl group, 2,2,2-trifluoroethyl Group, 1,1,2,2,2-pentafluoroethyl group, 2,2,3,3,3-pentafluoropropyl group, hydroxymethyl group, hydroxyethyl group, carboxylmethyl group, carboxylethyl group, methoxyethyl Group, benzyl group, p-fluorobenzyl group, p-methoxybenzyl group, p-methyl group Jill group, and phenylethyl group.

Preferable R ¹ , R ² , R ³ , R ⁴ , and R ⁵ each independently include a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, an ethyl group, or a normal propyl group, and more preferably A hydrogen atom is mentioned.
Preferable R ⁶ is independently a hydrogen atom, a chlorine atom, a bromine atom, a cyano group, a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, an isobutyl group, a secondary butyl group, or a tertiary butyl group. , Trifluoromethyl group, hydroxymethyl group, hydroxyethyl group, carboxymethyl group, methoxy group, ethoxy group, normal propoxy group, isopropoxy group, phenyl group, pentafluorophenyl group, anisole group, or tolyl group, More preferably, a hydrogen atom or a methoxy group is mentioned.

M includes Mn (II), Mn (III), Fe (II), Fe (III), Co (II), Co (III), or Ni (II), preferably Fe (II), Fe (III) or Co (II) is mentioned, More preferably, Co (II) is mentioned.
X includes CF ₃ SO ₃ ⁻ , CH ₃ —Ph—SO ₃ ⁻ , NCS ⁻ , CN ⁻ , Cl ⁻ , Br ⁻ , BF ₄ ⁻ , BPh ₄ ⁻ , ClO ₄ ⁻ , or PF ₆ ^−. Preferably, BF ₄ ^- is used. N is 2 or 3.

The terpyridine ligand constituting the metal complex of the above formula (1) is, for example, GR Pabst and J. Sauer, Tetrahedron Letters, 39, 6687-6690 (1998), Burstall FH, J. Chem. Soc., 1938, It can be synthesized according to the method described in 1662-1673.
In addition, the metal complex of the formula (1) includes, for example, a metal halide salt in an alcohol solvent such as methanol, a ketone solvent such as acetone, a halogen solvent such as chloroform, and a mixed solvent of an alcohol solvent and a halogen solvent. A terpyridine ligand synthesized by the above method in the presence of a sodium salt of X, or a terpyridine ligand and MXn (M, X, n are the same as above) in a solvent similar to the above. And the like).

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to the following Example.
Example 1 Production of Cobalt (II) Complex [Co (terpy) ₂ ] (BF ₄ ) ₂ A solution of ligand terpy (0.47 g, 2 mmol) in 20 ml of methanol was added to 20 ml of methanol with Co (BF ₄ ) When a solution containing ₂ 6H ₂ O (0.34 g, 1 mmol) was added with stirring, a brown solution was formed, and a solid precipitated. This solid was filtered and dried. The solid was recrystallized from methanol or acetone to obtain a brown single crystal.

[Magnetic susceptibility measurement]
Using a magnetometer (superconducting quantum interference device (SQUID) MPMS-7S, manufactured by Quantum Design) under a magnetic field of 0.5 T (Tesla), the sample (cobalt (II) complex [ 42.2 mg of Co (terpy) ₂ ] (BF ₄ ) ₂ ) was set to 5K, and the temperature was measured up to 400K at a heating rate of 2K / min. Then, it measured from 400K to 5K at the temperature decrease rate of 2K / min. FIG. 1 shows a χ _m T vs. T plot. △ is measured during the temperature rising process, and ▽ is the data measured during the temperature lowering process. T indicates temperature.
As shown in FIG. 1, it can be seen that the thermally-induced spin transition forms a cross hysteresis loop in the complex obtained in Example 1.

_{2 is} a χ _m T vs. T plot diagram of the cobalt (II) complex [Co (terpy) ₂ ] (BF ₄ ) ₂ obtained in Example 1. FIG.

Claims (4)

A magnetic recording element using a transition metal complex in which thermally induced spin transition forms a cross hysteresis loop,
The magnetic recording element, wherein the transition metal complex is represented by the formula (1).

{Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a halogen atom, a nitro group, a cyano group, or an alkyl group having 1 to 10 carbon atoms [this The alkyl group is a halogen atom, a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 3 carbon atoms, or a phenyl group (this phenyl group is a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 10 carbon atoms). Optionally substituted)). ], A cycloalkyl group having 3 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a phenyl group [this phenyl group is a halogen atom, an alkoxy group having 1 to 3 carbon atoms, or an alkyl group having 1 to 10 carbon atoms. It may be optionally substituted. ],
M represents Mn (II), Mn (III), Fe (II), Fe (III), Co (II), Co (III), or Ni (II);
X represents CF ₃ SO ₃ ⁻ , CH ₃ —Ph—SO ₃ ⁻ , NCS ⁻ , CN ⁻ , Cl ⁻ , Br ⁻ , BF ₄ ⁻ , BPh ₄ ⁻ , ClO ₄ ⁻ or PF ₆ ^−. Represents 2 or 3. }   The magnetic recording element according to claim 1, wherein the M is Fe (II), Fe (III), or Co (II). R ¹ , R ² , R ³ , R ⁴ , and R ⁵ each independently represent a hydrogen atom, a chlorine atom, a bromine atom, a methyl group, an ethyl group, or a normal propyl group;
R ⁶ is independently a hydrogen atom, chlorine atom, bromine atom, cyano group, methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, isobutyl group, secondary butyl group, tertiary butyl group, 2. A trifluoromethyl group, a hydroxymethyl group, a hydroxyethyl group, a carboxymethyl group, a methoxy group, an ethoxy group, a normal propoxy group, an isopropoxy group, a phenyl group, a pentafluorophenyl group, an anisole group, or a tolyl group. Or the magnetic recording element of 2. R ¹ , R ² , R ³ , R ⁴ , and R ⁵ represent a hydrogen atom, R ⁶ represents a hydrogen atom or a methoxy group, M represents Co (II), and X represents The magnetic recording element according to claim 1, wherein BF ₄ ⁻ and n is 2. 5.

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