Oxidation numbers derivation

The complete balance in the sense of oxidation numbers derived in such a way is not a general feature of clathrates. In particular, the defect structure of the alkaline-earth metal clathrate BagGe43D3 shows a balance with excess electrons ... 

The composition of sodium polysulfide solutions saturated with sulfur of zero oxidation number (S°) has also been studied at 25 and 80 °C (solutions in contact with elemental sulfur) [76]. In this case the ratio 8° 8 per polysulfide ion increases with increasing alkahnity. The maximum average number of sulfur atoms per polysulfide molecule was obtained as 5.4 at 25 °C and 6.0 at 80 °C and pH values of >12. Equilibrium constants for reactions as in Eqs. (26) and (27) have been derived assuming various models with differing numbers of polysulfide ions present. 

In contrast, it is accepted practice that referring to, for example, an iron(III) complex implies that this compound contains an iron ion with a high-, intermediate-, or low-spin electron configuration. Since n for a d" configuration is, at least in principle, a measurable quantity, it has been suggested [3] that an oxidation number n, which is derived from a known d configuration, should be specified as physical or spectroscopic oxidation number (state) [4—6]. 

A number of lower sulfur oxides have been described. Most of these oxides are derived from cyclic sulfur polymorphs and were usually prepared by oxidation of these molecules by organic peroxo acids. The oxides have the general formula SraO and n may vary from 5 to 10. For n = 7 even the dioxide S702 is known.4 Not all of these phases were characterized by X-ray diffraction, but the molecular structures are certain with respect to vibrational spectroscopy. The oxygen atom is in exo position with respect to the sulfur ring as it has been shown by X-ray diffraction for SgO and S70, respectively (Figure 2).5,6... 

The tetrafluoroammonium cation (NF/) has high electronegativity (the oxidation number of nitrogen is + 5) and high kinetic stability (NF4+ is isoelectronic with CF4).15 -17 It has been shown that in anhydrous hydrogen fluoride, benzene and its derivatives are fluorinated by tetrafluoroammonium tetrafluoroborate with substitution of hydrogen by fluorine.15-17... 

Modified Forms in Common Use. There are numerous situations in which the foregoing system does not meet all requirements. In the formation uf binary compounds, several elements exhibit more Ilian two states of oxidation. One method, recommended by the IUPAC, of handling these situations is the use of prefixes derived from Greek to indicate stoichiometric composition, e.g., titanium dichloride, TiCL and dinitrogen oxide (nitrous oxide) N 0. Other accepted methods ofindicating proportions of constituents are the Stock system (oxidation number) and the Ewens-Bassett (charge number) system. 

The writer4,179 analyzed the hydration energy differences derived from Eq. (31) for aqua ions, where E° is known for the process increasing the oxidation number from (z — 1) to z. It turns out that each transition group has a characteristic constant K such that... 

Based on the foregoing experimental results, the versatility of metal carbonyls and their derivatives in their reactions with liquid NH3 may be summarized as follows (/) substitution of CO or other ligands by NH3 without change in the oxidation number of the transition metal in question (2) conversion of covalent carbonyl complexes into ionic compounds by addition of NH3 molecules (3) base reactions" in which the transition metal is reduced to a carbonyl metalate with complementary oxidation of a CO ligand to CO(NH2)2 (4) valence disproportionations with... 

A number of complex niobium(V) oxide fluoride derivatives, such as... 

For molecules M2(NMe2)g, AHp = 6D(M-NMe2) + D(M M) the nature of the problem is immediately apparent. What value of D(M NMe2) should be transferred into the equation to derive D(M-M) Any error in D(M-NMe2) enters sixfold into the derived value. For example, the formal oxidation-number of the metal, M(III) in M2(NMe2)6 yields values of D(Mo -Mo) 200, and D(W-W) = 340 kJ mol-1 which are close to the respective metal-ligand bond enthalpy contributions. On the other hand, each metal atom has a valency of six, which yields values of D(HPM) (Mo, (788 24) ... 

Fluorine-containing cycloalkcncs are cleaved by oxidation to give polyfluoroalkanedicar-boxylic acids with the original number of carbon atoms. Hence, for example, oxidation of fluorinated cyclobutenes gives tetrafluorosuccinic acids, e.g. 7a. Similarly, oxidation of derivatives of perfluorocyclopentene gives perfluoropentanedioic acids, e.g. whilst perfluorocy-... 

Oxidative Addition is also common for those central atoms that can increase their oxidation state (see Oxidation Number) (equations 27 and 28). Substitution of halogen by organic groups is usefiil for the preparation of organo derivatives, as mentioned in Section 3.1 (equations 12 and 13). 

The oxidation numbers of the metals in the nitrosyl compounds depend on whether this ligand is considered NO , NO, or NO . However, it is generally assumed that, at least in the diamagnetic nitrosyl compounds which show N—0 stretching frequencies above 1700 cm.""S the nitrosyl group is to be considered as NO+ (75). Therefore, the nitrosyl compounds reported below are to be considered as nickel(O), palladium(O), and platinum (0) derivatives. 

The derivatives with triethylphosphine and ethylene, styrene, stilbene, and methylstyrene have been prepared from bispentan-2,4-dionatonickel and alkylaluminum compounds in the presence of the phosphine and the olefin 200). The oxidation number of nickel in these compounds is controversial because the compounds can be considered to be either trico-ordinated nickel(O) derivatives (1) or square planar nickel(II) derivatives (2). 

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