trivalent

• 三価の

関

tervalent

　 　

WordNet

1. having a valence of three

PrepTutorEJDIC

1. (原子価が)3価の

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/05/20 06:56:51」(JST)

wiki en

[Wiki en表示]

For other uses, see Valence (disambiguation).

"Multivalent" redirects here. For other uses, see Polyvalence (disambiguation).

In chemistry, the valence (or valency) of an element is a measure of its combining power with other atoms when it forms chemical compounds or molecules. The concept of valence was developed in the second half of the 19th century and was successful in explaining the molecular structure of inorganic and organic compounds. The quest for the underlying causes of valence led to the modern theories of chemical bonding, including Lewis structures (1916), valence bond theory (1927), molecular orbitals (1928), valence shell electron pair repulsion theory (1958), and all of the advanced methods of quantum chemistry.

Description

The combining power or affinity of an atom of an element was determined by the number of hydrogen atoms that it combined with. In methane, carbon has a valence of 4; in ammonia, nitrogen has a valence of 3; in water, oxygen has a valence of two; and in hydrogen chloride, chlorine has a valence of 1. Chlorine, as it has a valence of one, can be substituted for hydrogen, so phosphorus has a valence of 5 in phosphorus pentachloride, PCl₅. Valence diagrams of a compound represent the connectivity of the elements, with lines drawn between two elements, sometimes called bonds, representing a saturated valency for each element. Examples are

Compound	H2	CH4	C3H8	C2H2	NH3	NaCN	H2S	H2SO4	Cl2O7
Diagram
Valencies	Hydrogen 1	Carbon 4 Hydrogen 1	Carbon 4 Hydrogen 1	Carbon 4 Hydrogen 1	Nitrogen 3 Hydrogen 1	Sodium 1 Carbon 4 Nitrogen 3	Sulfur 2 Hydrogen 1	Sulfur 6 Oxygen 2 Hydrogen 1	Chlorine 7 Oxygen 2

Valence only describes connectivity; it does not describe the geometry of molecular compounds, or what are now known to be ionic compounds or giant covalent structures. A line between atoms does not represent a pair of electrons as it does in Lewis diagrams.

Modern definitions

Valence is defined by the IUPAC as:-

The maximum number of univalent atoms (originally hydrogen or chlorine atoms) that may combine with an atom of the element under consideration, or with a fragment, or for which an atom of this element can be substituted. .

An alternative modern description is:-

The number of hydrogen atoms that can combine with an element in a binary hydride or twice the number of oxygen atoms combining with an element in its oxide or oxides. This definition differs from the IUPAC definition as an element can be said to have more than one valence.

History

The etymology of the word "valence" traces back to 1425, meaning "extract, preparation," from Latin valentia "strength, capacity," and the chemical meaning referring to the "combining power of an element" is recorded from 1884, from German Valenz.

William Higgins' combinations of ultimate particles (1789)

In 1789, William Higgins published views on what he called combinations of "ultimate" particles, which foreshadowed the concept of valency bonds. If, for example, according to Higgins, the force between the ultimate particle of oxygen and the ultimate particle of nitrogen were 6, then the strength of the force would be divided accordingly, and likewise for the other combinations of ultimate particles (see illustration).

The exact inception, however, of the theory of chemical valencies can be traced to an 1852 paper by Edward Frankland, in which he combined the older theories of free radicals and “type theory” with thoughts on chemical affinity to show that certain elements have the tendency to combine with other elements to form compounds containing 3, i.e., in the three atom groups (e.g., NO₃, NH₃, NI₃, etc.) or 5, i.e., in the five atom groups (e.g., NO₅, NH₄O, PO₅, etc.), equivalents of the attached elements. It is in this manner, according to Frankland, that their affinities are best satisfied. Following these examples and postulates, Frankland declares how obvious it is that

“ A tendency or law prevails (here), and that, no matter what the characters of the uniting atoms may be, the combining power of the attracting element, if I may be allowed the term, is always satisfied by the same number of these atoms. ”

This “combining power” was afterwards called quantivalence or valency (and valence by American chemists).

Common valences

For elements in the main groups of the periodic table, the valence can vary between one and seven.

Group	Valence 1	Valence 2	Valence 3	Valence 4	Valence 5	Valence 6	Valence 7	Typical valencies
1 (I)	NaCl							1
2 (II)		MgCl2						2
13 (III)			BCl3, AlCl3 Al2O3					3
14 (IV)		CO		CH4				4
15 (V)		NO	NH3 PH3 As2O3	NO2	N2O5 PCl5			3 and 5
16 (VI)		H2O H2S		SO2		SO3		2 and 6
17 (VII)	HCl			ClO2			Cl2O7	1 and 7

Many elements have a common valence related to their position in the periodic table, and nowadays this is rationalised by the octet rule. The Latin/Greek prefixes uni/mono, bi/di, ter/tri, quadri/tetra, quinque/penta are used to describe ions in the one, two, three, four or five charge states. Polyvalence or multivalence refers to species that are not restricted to a specific number of valence bonds. Species with a single charge are univalent (monovalent)). For example, the Cs⁺ cation is a univalent or monovalent cation, whereas the Ca²⁺ cation is a divalent cation, and the Fe³⁺ cation is a trivalent cation. Unlike Cs and Ca, Fe can also exist in other charge states, notably 2+ and 4+, and is thus known as a multivalent (polyvalent) ion.

Valence versus oxidation state

Because of the ambiguity of the term valence, nowadays other notations are used in practice. Beside the system of oxidation numbers as used in Stock nomenclature for coordination compounds, and the lambda notation, as used in the IUPAC nomenclature of inorganic chemistry, "oxidation state" is a more clear indication of the electronic state of atoms in a molecule.

The "oxidation state" of an atom in a molecule gives the number of valence electrons it has gained or lost. In contrast to the valency number, the oxidation state can be positive (for an electropositive atom) or negative (for an electronegative atom).

Elements in a high oxidation state can have a valence higher than four. For example, in perchlorates, chlorine has seven valence bonds and ruthenium, in the +8 oxidation state in ruthenium tetroxide, has eight valence bonds.

Examples

(valencies according to the number of valence bonds definition and conform oxidation states)

COMPOUND	FORMULA	VALENCE	OXIDATION STATE
Hydrogen chloride	HCl	H = 1   Cl = 1	H = +1   Cl = −1
Perchloric acid *	HClO4	H = 1   Cl = 7   O = 2	H = +1   Cl = +7   O = −2
Sodium hydride	NaH	Na = 1   H = 1	Na = +1   H = −1
Ferrous oxide **	FeO	Fe = 2   O = 2	Fe = +2   O = −2
Ferric oxide **	Fe2O3	Fe = 3   O = 2	Fe = + 3   O = −2

* The univalent perchlorate ion (ClO₄⁻) has valence 1.

• • Iron oxide appears in a crystal structure, so no typical molecule can be identified.
    

  In ferrous oxide, Fe has oxidation number II, in ferric oxide, oxidation number III.

Examples where valences and oxidation states differ due to bonds between identical atoms:

COMPOUND	FORMULA	VALENCE	OXIDATION STATE
Chlorine	Cl2	Cl = 1	Cl = 0
Hydrogen peroxide	H2O2	H = 1   O = 2	H = +1   O = −1
Acetylene	C2H2	C = 4   H = 1	C = −1   H = +1
Mercury(I) chloride	Hg2Cl2	Hg = 2   Cl = 1	Hg = +1   Cl = −1

Valences may also be different from absolute values of oxidation states due to different polarity of bonds. For example, in dichloromethane, CH₂Cl₂, carbon has valence 4 but oxidation state 0.

"Maximum number of bonds" definition

Frankland took the view that the valence (he used the term "atomicity") of an element was a single value that corresponded to the maximum value observed. The number of unused valencies on atoms of what are now called the p-block elements is generally even, and Frankland suggested that the unused valencies saturated one another. For example, nitrogen has a maximum valence of 5, in forming ammonia two valencies are left unattached; sulfur has a maximum valence of 6, in forming hydrogen sulphide four valencies are left unattached.

The International Union of Pure and Applied Chemistry (IUPAC) has made several attempts to arrive at an unambiguous definition of valence. The current version, adopted in 1994:

The maximum number of univalent atoms (originally hydrogen or chlorine atoms) that may combine with an atom of the element under consideration, or with a fragment, or for which an atom of this element can be substituted.

Hydrogen and chlorine were originally used as examples of univalent atoms, because of their nature to form only one single bond. Hydrogen has only one valence electron and can form only one bond with an atom that has an incomplete outer shell. Chlorine has seven valence electrons and can form only one bond with an atom that donates a valence electron to complete chlorine's outer shell. However, chlorine can also have oxidation states from +1 to +7 and can form more than one bond by donating valence electrons.

Although hydrogen has only one valence electron, it can form bonds with more than one atom in hypervalent bonds. In the bifluoride ion ([HF
2]−
), for example, it forms a three-center four-electron bond with two fluoride atoms:

Another example is the Three-center two-electron bond in diborane (B₂H₆).

Maximum valences of the elements

Maximum valences for the elements are based on the data from list of oxidation states of the elements.

Maximum valences of the elements
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18
Group →
↓ Period
1	1 H																	2 He
2	3 Li	4 Be											5 B	6 C	7 N	8 O	9 F	10 Ne
3	11 Na	12 Mg											13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
4	19 K	20 Ca	21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
5	37 Rb	38 Sr	39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
6	55 Cs	56 Ba		72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
7	87 Fr	88 Ra		104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Uut	114 Fl	115 Uup	116 Lv	117 Uus	118 Uuo
			57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu
			89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr
Maximum valences are based on the List of oxidation states of the elements
0 1 2 3 4 5 6 7 8 9 Unknown Background color shows maximum valence of the chemical element black=solid green=liquid red=gas grey=unknown Color of the atomic number shows state of matter (at 0 °C and 1 atm) Primordial From decay Synthetic Border shows natural occurrence of the element

Covalence

The term covalence is attributed to Irving Langmuir. He stated that "the number of pairs of electrons which any given atom shares with the adjacent atoms is called the covalence of that atom." The prefix co- means "together", so that a co-valent bond means that the atoms share valence. Subsequent to this, it is now more common to speak of covalent bonds rather than "valence", which has fallen out of use in higher level work with the advances in the theory of chemical bonding, but is still widely used in elementary studies where it provides a heuristic introduction to the subject.

See also

• Valence electron
• Abegg's rule
• Oxidation state

References

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 成人における季節性インフルエンザワクチン seasonal influenza vaccination in adults
• 2. インフルエンザと妊娠 influenza and pregnancy
• 3. 合併症リスクの低い成人癌患者における発熱性好中球減少症候群の治療および予防 treatment and prevention of neutropenic fever syndromes in adult cancer patients at low risk for complications
• 4. 最新の診療アップデート practice changing updates
• 5. ポリオワクチン poliovirus vaccination

English Journal

• A novel FRET 'off-on' fluorescent probe for the selective detection of Fe(3+), Al(3+) and Cr(3+) ions: Its ultrafast energy transfer kinetics and application in live cell imaging.

• Chereddy NR1, Nagaraju P2, Niladri Raju MV2, Krishnaswamy VR3, Korrapati PS3, Bangal PR4, Rao VJ5.
• Biosensors & bioelectronics.Biosens Bioelectron.2015 Jun 15;68:749-56. doi: 10.1016/j.bios.2015.01.074. Epub 2015 Feb 7.
• A rhodamine-naphthalimide dyad probe, 1, that selectively responds to the addition of trivalent metal ions (Fe(3+) or Al(3+) or Cr(3+)) via ultrafast Förster resonance energy transfer (FRET) from naphthalimide to rhodamine is designed and synthesized. 1 is highly selective to the trivalent metal io
• PMID 25682503

• TAME5OX, abiotic siderophore analogue to enterobactin involving 8-hydroxyquinoline subunits: Thermodynamic and photophysical studies.

• Akbar R1, Baral M2, Kanungo BK3.
• Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy.Spectrochim Acta A Mol Biomol Spectrosc.2015 May 5;142:246-59. doi: 10.1016/j.saa.2015.01.104. Epub 2015 Feb 9.
• The synthesis, thermodynamic and photophysical properties of trivalent metal complexes of biomimetic nonadentate analogue, 5,5'-(2-(((8-hydroxyquinolin-5-yl)methylamino)methyl)-2-methylpropane-1,3-diyl)bis(azanediyl)bis(methylene)diquinolin-8-ol (TAME5OX), have been described. Combination of absorpt
• PMID 25703371

• Development of a time-resolved fluorescence probe for evaluation of competitive binding to the cholecystokinin 2 receptor.

• Elshan NG1, Jayasundera T2, Weber CS2, Lynch RM3, Mash EA4.
• Bioorganic & medicinal chemistry.Bioorg Med Chem.2015 Apr 15;23(8):1841-8. doi: 10.1016/j.bmc.2015.02.028. Epub 2015 Feb 26.
• The synthesis, characterization, and use of Eu-DTPA-PEGO-Trp-Nle-Asp-Phe-NH2 (Eu-DTPA-PEGO-CCK4), a luminescent probe targeted to cholecystokinin 2 receptor (CCK2R, aka CCKBR), are described. The probe was prepared by solid phase synthesis. A Kd value of 17±2nM was determined by means of saturation
• PMID 25769518

Japanese Journal

• 工業用硬質めっきの環境適応化 (特集 めっき技術の未来を見つめる)

• 眞保 良吉
• 精密工学会誌 78(12), 1038-1042, 2012-12
• NAID 40019513999

• Cross-reactive antibody response to the pandemic A (H1N1) 2009 influenza virus induced by vaccination with a seasonal trivalent influenza vaccine : a longitudinal study of three influenza seasons in Japan

• Uno Shingo,Kimachi Kazuhiko,Matsuo Fujio [他]
• Microbiology and immunology 56(12), 810-816, 2012-12
• NAID 40019504318

• 2011年全国BCGワクチン,経口生ポリオワクチン,DPT3種混合ワクチン累積接種率調査報告

• ？山 直秀,崎山 弘,岡部 信彦 [他]
• 日本医師会雑誌 141(7), 1549-1555, 2012-10
• NAID 40019432574

Related Links

• trivalentの意味 - 英和辞書 - goo辞書

trivalentとは。意味や和訳。[形]化学〈原子価が〉3価の. - goo辞書は国語、英和、和英、中国語、百科事典等からまとめて探せる辞書検索サービスです。 ... 辞書すべて 国語 類語 英和 和英 中日 日中 ※「説明文に含む」「見出し語に ...

• Trivalent Data Systems Ltd

Introducing the release of TECIS: A complete Web Hosted solution for GHS compliance. Trivalent has been working for the last 5 years to take our Windows based software systems to the Web. The problem with slow servers, slow ...

Related Pictures

---

★リンクテーブル★

リンク元	「三価」「tervalent」

「三価」

　　[★]

英

trivalent、tervalent

「tervalent」

　　[★]

• 三価の

関

trivalent