In inorganic chemistry, a Nowotny chimney ladder phase (NCL phase) is a particular intermetallic crystal structure found with certain binary compounds. NLC phases are generally tetragonal and are composed of two separate sublattices. The first is a tetragonal array of transition metal atoms, generally from group 4 through group 9 of the periodic table. Contained within this array of transition metal atoms is a second network of main group atoms, typically from group 13 (boron group) or group 14 (carbon group). The transition metal atoms form a chimney with helical zigzag chain. The main-group elements form a ladder spiraling inside the transition metal helix.
The phase is named after one of the early investigators H. Nowotny. [1] [2] [3] Examples are RuGa2, Mn4Si7, Ru2Ge3, Ir3Ga5, Ir4Ge5 V17Ge31, Cr11Ge19, Mn11Si19, Mn15Si26, Mo9Ge16, Mo13Ge23, Rh10Ga17, and Rh17Ge22. [4]
In RuGa2 the ruthenium atoms in the chimney are separated by 329 pm. The gallium atoms spiral around the Ru chimney with a Ga–Ga intrahelix distance of 257 pm. The view perpendicular to the chimney axis is that of a hexagonal lattice with gallium atoms occupying the vertices and ruthenium atoms occupying the center. Each gallium atom bonds to 5 other gallium atoms forming a distorted trigonal bipyramid. The gallium atoms carry a positive charge and the ruthenium atoms have a formal charge of −2 (filled 4d shell). [5]
In Ru2Sn3 the ruthenium atoms spiral around the tin inner helix. In two dimension the Ru atoms form a tetragonal lattice with the tin atoms appearing as triangular units in the Ru channels. [6]
The occurrence of a LCP phase can be predicted by the so-called 14 electron rule. In it the total number of valence electrons per transition metal atom is 14. [7] [8] [9]
Lutetium is a chemical element; it has symbol Lu and atomic number 71. It is a silvery white metal, which resists corrosion in dry air, but not in moist air. Lutetium is the last element in the lanthanide series, and it is traditionally counted among the rare earth elements; it can also be classified as the first element of the 6th-period transition metals.
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to other atoms were fully ionic. It describes the degree of oxidation of an atom in a chemical compound. Conceptually, the oxidation state may be positive, negative or zero. While fully ionic bonds are not found in nature, many bonds exhibit strong ionicity, making oxidation state a useful predictor of charge.
Metal carbonyls are coordination complexes of transition metals with carbon monoxide ligands. Metal carbonyls are useful in organic synthesis and as catalysts or catalyst precursors in homogeneous catalysis, such as hydroformylation and Reppe chemistry. In the Mond process, nickel tetracarbonyl is used to produce pure nickel. In organometallic chemistry, metal carbonyls serve as precursors for the preparation of other organometallic complexes.
The Hunsdiecker reaction is a name reaction in organic chemistry whereby silver salts of carboxylic acids react with a halogen to produce an organic halide. It is an example of both a decarboxylation and a halogenation reaction as the product has one fewer carbon atoms than the starting material and a halogen atom is introduced its place. A catalytic approach has been developed.
Ruthenium(IV) oxide is the inorganic compound with the formula RuO2. This black solid is the most common oxide of ruthenium. It is widely used as an electrocatalyst for producing chlorine, chlorine oxides, and O2. Like many dioxides, RuO2 adopts the rutile structure.
Metal nitrosyl complexes are complexes that contain nitric oxide, NO, bonded to a transition metal. Many kinds of nitrosyl complexes are known, which vary both in structure and coligand.
In chemistry, a Zintl phase is a product of a reaction between a group 1 or group 2 and main group metal or metalloid. It is characterized by intermediate metallic/ionic bonding. Zintl phases are a subgroup of brittle, high-melting intermetallic compounds that are diamagnetic or exhibit temperature-independent paramagnetism and are poor conductors or semiconductors.
Trimethylsulfonium is an organic cation with the chemical formula (CH3)3S+.
Levopropylhexedrine (Eventin) is an adrenergic alkylamine used as an anorectic in Germany and patented by Smith Kline & French in 1947. It has also been used in the anticonvulsant preparation barbexaclone in combination with phenobarbital to offset sedation. Levopropylhexedrine is the levorotatory S-enantiomer of propylhexedrine. The dextrorotatory counterpart is known as dextropropylhexedrine.
Boron monofluoride or fluoroborylene is a chemical compound with the formula BF, one atom of boron and one of fluorine. It is an unstable gas, but it is a stable ligand on transition metals, in the same way as carbon monoxide. It is a subhalide, containing fewer than the normal number of fluorine atoms, compared with boron trifluoride. It can also be called a borylene, as it contains boron with two unshared electrons. BF is isoelectronic with carbon monoxide and dinitrogen; each molecule has 14 electrons.
The MAX phases are layered, hexagonal carbides and nitrides which have the general formula: Mn+1AXn, (MAX) where n = 1 to 4, and M is an early transition metal, A is an A-group (mostly IIIA and IVA, or groups 13 and 14) element and X is either carbon and/or nitrogen. The layered structure consists of edge-sharing, distorted XM6 octahedra interleaved by single planar layers of the A-group element.
Binary compounds of silicon are binary chemical compounds containing silicon and one other chemical element. Technically the term silicide is reserved for any compounds containing silicon bonded to a more electropositive element. Binary silicon compounds can be grouped into several classes. Saltlike silicides are formed with the electropositive s-block metals. Covalent silicides and silicon compounds occur with hydrogen and the elements in groups 10 to 17.
Ruthenium hexafluoride, also ruthenium(VI) fluoride (RuF6), is a compound of ruthenium and fluorine and one of the seventeen known binary hexafluorides.
4-Octyne, also known as dipropylethyne, is a type of alkyne with a triple bond at its fourth carbon (the '4-' indicates the location of the triple bond in the chain). Its formula is C8H14.
The inorganic imides are compounds containing an ion composed of nitrogen bonded to hydrogen with formula HN2−. Organic imides have the NH group, and two single or one double covalent bond to other atoms. The imides are related to the inorganic amides (H2N−), the nitrides (N3−) and the nitridohydrides (N3−•H−).
Manganese disilicide (MnSi2) is an intermetallic compound, a silicide of manganese. It is a non-stoichiometric compound, with a silicon deficiency expressed as MnSi2–x. Crystal structures of many MnSi2–x compounds resemble a chimney ladder and are called Nowotny phases. They include MnSi2 (x=0), Mn4Si7 (x=0.250), Mn11Si19 (x=0.273), Mn15Si26 (x=0.267) and Mn27Si47 (x=0.259). These phases have very similar unit cells whose length varies from 1.75 nm for MnSi2 or Mn4Si7, which have almost the same structures, to 11.8 nm for Mn27Si47.
Ruthenium(III) bromide is a chemical compound of ruthenium and bromine with the formula RuBr3. It is a dark brown solid that decomposes above 400 °C.
Phosphide carbides or carbide phosphides are compounds containing anions composed of carbide (C4−) and phosphide (P3−). They can be considered as mixed anion compounds. Related compounds include the phosphide silicides, germanide phosphides, arsenide carbides, nitride carbides and silicide carbides.
Germyl, trihydridogermanate(1-), trihydrogermanide, trihydridogermyl or according to IUPAC Red Book: germanide is an anion containing germanium bounded with three hydrogens, with formula GeH−3. Germyl is the IUPAC term for the –GeH3 group. For less electropositive elements the bond can be considered covalent rather than ionic as "germanide" indicates. Germanide is the base for germane when it loses a proton.
Caesium sesquioxide is a chemical compound with the formula Cs2O3 or more accurately Cs4O6. It is an oxide of caesium containing oxygen in different oxidation states. It consists of caesium cations Cs+, superoxide anions O−2 and peroxide anions O2−2. Caesium in this compound has an oxidation state of +1, while oxygen in superoxide has an oxidation state of −1/2 and oxygen in peroxide has an oxidation state of −1. This compound has a structural formula of (Cs+)4(O−2)2(O2−2). Compared to the other caesium oxides, this phase is less well studied, but has been long present in the literature. It can be created by thermal decomposition of caesium superoxide at 290 °C.