Dithionite Complexes

Dithionite does not act as a ligand in very many compounds. The structures of the complexes that do form are interesting insights into the bonding in dithionite (what orbital provides the pair of electons and what changes in bonding occur on complexation).

1. J. Organometal. Chem., 1975: Title: SYNTHESIS OF A TRANSITION METAL-DITHIONITE COMPLEX [pretty sketchy work but the first report] LINK2. J. Organometal. Chem., 1980: Title: SYNTHESIS, CHARACTERIZATION AND SOME REACTIONS OFORGANOMETALLIC COMPLEXES CONTAINING BRIDGNG DITHIONITE LIGAND [An extension of the previous publication to other metal systems] LINK 3. Organometallics, 1985: Title: Reduction of SO2 by (C5R5)M(C0)3H (M = Mo, W; R = H, Me).Chemistry and Structures of (C5H5)Nlo(CO),(SO,H),the FirstExample of Insertion of SO2 into a M-H Bond, and[ (C5M5,)Mo(CO)3],(S2O4),S-Bonded Dithionite Complex [Complex is described by authors as "unexpected" but still recovered in 31% yield, note the complex is to the C2h dithionite structure and the S-S distance is 3.692 A] LINK4. J. Amer. Chem. Soc., 1999: Title: Oxidation of the Sulfide Ligands to SO42- in the Dinuclear Complex{RuCl[P(OMe)3]2}2(µ-S2)(µ-Cl)(µ-N2H4): Synthesis andCharacterization of {RuCl[P(OMe)3]2}2(µ-S2)(µ-Cl)(µ-N2H4)+HSO4-,{RuCl2[P(OMe)3]2}2(µ-S)(µ-N2H4), and{RuCl[P(OMe)3]2}2(µ-S2O5)(µ-N2H4) [The dithionite complex is more of an intermediate than an isolated product but the mechanism is amusing] LINK

5. Angew. Chemie, 2006: Title: Direct Observation of Photochromic Dynamics in the Crystalline State of an Organorhodium Dithionite Complex [Nice work but a classic case of duplicate publication, the S-S distance is 2.330 A and note the energetic similarity of the S-S and S-O bonded dithionites] LINK and LINK

6. J. Organometal. Chem., 2007: Title: Synthesis and structural characterization of a photoresponsive organodirhodium complex with active S–S bonds:[(CpPhRh)2(l-CH2)2(l-O2SSO2)] (CpPh = g5-C5Me4Ph) [it may seem like a simple extension but these complexes are pretty remarkable, S-S in cis is 2.295 A and S-S in trans is 2.299 A, how is that possible?] LINK

Dithionite Preparation and Purification

N.B. Many of the publications that use dithionite give an "in house" method for the preparation of pure dithionite from commercial samples that are in fact some form of simplification of reference 3 below, see for example the experimental section of these papers (LINK and LINK). In addition the X-ray structural references below all have specific syntheses (such as LINK which gives the synthesis for SnS2O4 as metallic tin in 7.5% water in liquid sulphur dioxide with time)

1. Indust. Engineer. Chem., 1969: Title: Formation of Sodium Dithionite from Sodium Amalgam and Sulfur Dioxide [old school industrial preparation] LINK


2. US Military Research Report, 1988: Title : Investigation of Li/SO2 Cell Hazards. 3. RamanSpectroscopy of Lithium Dithionite. [Raman spectroscopy reveals that lithium dithionite undergoes a low temperature lattice transformation that demonstrates the existence of two forms of dithionite. Transition metal ions were briefly evaluated] LINK


3. Biochimica Biophysica Acta, 1991: Title: A Method for Preparing Analytically Pure Sodium Dithionite [Detailed review of prior syntheses and methods with detailed procedure for purification] LINK


4. US Patent, 1992: Title: Stabilized Sodium Dithionite [additives to industrial lots of dithionite can reduce decomposition] LINK

5. J. Chromatog., 1992: Title: CLIX*. Determination of dithionite (S2O4)2- and hydroxymethanesulphinate (HOCH2S02; Rongalite) by ion-pair chromatography [Chromatographic method of preparing pure dithionite, good discussion of impurities generated by decomposition in aqueous solutions] LINK

6. J. Electrochem. Soc., 1998: Title: Electrosynthesis of sodium hydrosulfite - II. The effect of cathode material [method of synthesis that eliminates thiosulphate impurity] LINK


7. Online Patent, Current: Title: Process for Producing Dithionites [gives detailed small batch synthesis via formate] LINK

Dithionite - Sulphur Dioxide Radical Anion Equilibrium

1. Inorganica. Chem. Acta, 1986: Title: Infrared and Raman Study of Matrix Isolated M(S02) Molecules.The Structure of the Molecular Ion S02- [Reduction of SO2 in matrix no dithionite] LINK

2. New J. Chem., 1993: Title: SOLUTIONS OF DIISOPROPYLETHYLAMINE AND SULFUR-DIOXIDE .1. SOURCE OF SO2-CENTER-DOT AND SULFOXYLATE ANION [] LINK

3. Chem. Phys. Lett., 1994, Title: Ab initio study of the electronic structureof the ( S02) (SO2- ) dimer A one-electron S-S bond formation? [theoretical study on bonding between radical anion and neutral SO2] LINK4. J. Electrochem. Soc., 1995: Title: IN-SITU SPECTROELECTROCHEMICAL STUDIES ON THE SULFUR-DIOXIDE REDUCTION IN DIMETHYLSULFOXIDE [] LINK

5. Int. J. Mass Spec., 1997: Title: Electronic structures of (SO2)(n)(-) as studied by photoelectron spectroscopy [This work shows that the SO2-SO2- anion acts as a stable core for the addtion of more neutral molecules to form larger clusters] LINK

6. J. Electroanal. Chem., 1999: Title: Mechanism of the electrochemical reduction of sulfur dioxide innon-aqueous solvents [First mention of polythionites in literature, good review of previous work] LINK
7. New J. Chem., 1999: Title: Spectroscopic characterization of the blue and red complexes in reduced SO solutions in HMPA2 [Extension of previous paper by same authors, first experimental proof of identity of coloured species in SO2 reductions] LINK

8. J. Chem. Phys., 2000 , Title: The vibrational spectra of molecular ions isolated in solid neon. XVI. SO2+ , SO2- , and (SO2)2- [] LINK

9. Chem. Phys. Lett., 2001, Title: Dissociative photodetachment of SO2-SO2-: evidence for the S-O bound dimer [Bond dissociation measured/calculated for SO2-SO2- dimer] LINK 10. Chem. Phys. Lett., 2002: Title: Three-body dissociation dynamics of (SO2)3 studied
through dissociative photodetachment of SO2- [measurements on the radical anion + 2 SO2 molecule as a cluster] LINK

11. J. Phys. Chem. B, 2005: Title: Cathodic Reduction of Bisulfite and Sulfur Dioxide in Aqueous Solutions on CopperElectrodes: An Electrochemical ESR Study [Cathode reduction sounds like magic to me but they seem to have done their work and have evidence for similar chemistry to what was seen in previous work but in a completely different chemical environment] LINK

12. J. Phys. Chem. C, 2008: Title: Electroreduction of Sulfur Dioxide in Some Room-Temperature Ionic Liquids [good review of previous work on this system confirming some results] LINK

Soluble Dithionite Salts

1. Tet. Lett., 1977: Title: ORANGE BENZENE. NEUTRAL DICHROMATE OXIDATIONS IN ORGANIC SOLVENTS [not on dithionite but use of cation exchage agents to make insoluble dianion soluble in non-aqueous solutions] LINK

2. Bioinorg. Chem. 1978: Title: CROWN ETHER COMPLEXES OF SODIUM DITIONITE AND THEIR USES AS REDUCING AGENTS [products are poorly characterized but earliest indication that salts with larger cations are soluble] LINK

3. J. Chem. Soc., Chem. Commun., 1979: Title: Stereochemistry of Methylcyclohexanones Reduction by Sodium Dithionite under Conventional and Phase Transfer Conditions [product not isolated or characterized] LINK

4. Inorg. Chem., 1987, : Title: Synthesis of Tetraethylammonium Dithionite and Its Dissociation to the Sulfur Dioxide Radical Anion in Organic Solvents [Cation exchange using column chromatography, isolated and characterized, equilibriums determined] LINK

5. Inorg. Chem., 1991: Title: Spectroscopic Evidence for a Centrosymmetric Dithionite Anion in the Solid State:Vibrational Spectroscopy of Tetraethylammonium Dithionite [Spectroscopic study on sample provided by previous authors to determine structure of anion] LINK 6. Reactive Polymers, 1991: Title: REDUCTIONS WITH POLYMER SUPPORTED DITHIONITE ANIONS - REGIOSELECTIVITY IN CONJUGATED SYSTEMS [not exactly a soluble dithionite but ion exchange involving dithionite] LINK

7. J. Chem. Soc., Chem. Commun., 1992: Title: A New Electron Mediator: Reduction by Na2S204 in Organic Media of a Novel Viologen Functionalized with Crown Ether Structure [pretty clever work, authors wanted efficient reduction with dithionite so they attached crown ethers to their starting material, seems to have worked, ominous comment on the reductions working better when add small amout of water to non-aqueous solvents though] LINK

Dithionite Review Articles

1. Bull. Soc. Chim. Fr., 1986: Title: CHEMICAL REDUCTIONS WITH SODIUM DITHIONITE [French language review of basic chemistry of dithionite and its use as reducing agent in organic chemical reaction] LINK

2. Uspekhi Khimii, 2001: Title: Novel trends in chemistry of sulfur-containing reductants [Russian language review of basic chemistry of dithionite with emphasis on its use in organic chemical reductions, translated abstract given below, link is to full citation with references ] LINK

Abstract: Data on structure, synthesis, stability, and reactivity of sulfur-containing reductants with C - S and S - S bonds - sodium dithionite, sodium hydroxymethanesulfinate, as well as thiourea oxides,- are surveyed. Reactions of anaerobic and aerobic degradation of sulfur-containing reductants are discussed. Application of these compounds to study non-linear phenomena in chemical kinetics, as well as in guanidine synthesis, is considered.

3. Wikipedia Links: Dithionite and Sodium dithionite

Dithionite Theoretical Studies

1. Chem. Phys. Lett., 1989 : Title: MOLECULAR-STRUCTURE AND VIBRATIONAL-SPECTRA OF DITHIONITE ION BY ABINITIO CALCULATIONS [calculations at the 3-21G* level shows C2h most stable in solution, notable quote from paper "we believe that further refinements of the basis set will not change these values greatly"] LINK

]




2. J. Amer. Chem. Soc., 1993 : Title: A DENSITY-FUNCTIONAL STUDY OF SULFOXY ANIONS CONTAINING SULFUR-SULFUR BONDS [calculations at the LCAO-Xalpha level shows dithionite unstable in the gas phase but able to optimize using point charge envelopes] LINK











3. J. Molec. Struct. (THEOCHEM), 1993 : Title: SULFUR-COMPOUNDS .162. GEOMETRIES AND ENERGIES OF THE RADICAL-ANION SO2- AND OF 3 ISOMERIC STRUCTURES OF THE DITHIONITE ANION S2O42- [Calculations at the MP2/6-311+G(2d,p)//6-31G* show that dithionite in the gas phase is unstable] LINK

4. J. Phys. Chem. A, 1998 : Title: Structures and energies of various isomers of dithionous acid, H2S2O4, and of its anion HS2O4- [calculation at the MP2/6-311++G-(d,p) level confirms earlier work] LINK
5. Inorg. Chem., 2006 Title: Pericyclic transition-state-like aromaticity in the inorganic ions Se2I42+ and S2O42- [calculations at the MPW1PW91 level indicate that the bonding may be interpreted as through space conjugation leading to aromaticity] LINK

Dithionite Structure References

1. J. Amer. Chem. Soc., 1956 :Title: STRUCTURE OF DITHIONITE [Structure Na2S2O4] LINK (The structure is also published by Dunitz the same year in Acta Cryst but that file is not available this LINK is to the Web of Science citation file for the paper)

2. Acta Cryst. B, 1978:Title: NATURE OF S-S BONDS IN DIFFERENT COMPOUNDS .5. CRYSTAL-STRUCTURE OF ZNS2O4.PYRIDINE [Structure of ZnS2O4-pyridine] LINK












3. Acta Chemica Scand., 1982:Title: THE CRYSTAL-STRUCTURE OF TIN(II) DITHIONITE, SN2(S2O4)2 [Structure of Sn2(S2O4)2] LINK

4. Journal of Crystallographic and Spectroscopic Research, 1992: Title: A STRUCTURAL STUDY OF SODIUM DITHIONITE AND ITS EPHEMERAL DIHYDRATE - A NEW CONFORMATION FOR THE DITHIONITE ION [Structure of Na2(S2O4)-2H20 and redetermination of earlier structure of Na2S2O4, best structural review] LINK