|
Reticular Materials
Reticular chemistry is a branch of chemistry that focuses on the design and synthesis of crystalline, highly ordered structures by connecting molecular building blocks through strong bonds, such as covalent or coordination bonds, to make open frameworks. This field was pioneered by Omar M. Yaghi, who has been recognized by the community for his groundbreaking contributions. Reticular chemistry is at the intersection of inorganic chemistry, organic chemistry, and materials science, revolutionizing how functional materials are developed. Key features of reticular materials The most notable examples of reticular chemistry are metal–organic frameworks (MOFs) which consist of metal ions or clusters connected by anionic organic linkers and covalent organic frameworks (COFs) that consist of organic molecules linked via covalent bonds. Another example includes zeolitic imidazolate frameworks (ZIFs). Overarching key features of reticular materials are the following: Order and por ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omar Yaghi 413953 By Christopher Michel 1-7-2025
Umar ibn al-Khattab (; ), also spelled Omar, was the second Rashidun caliph, ruling from August 634 until his assassination in 644. He succeeded Abu Bakr () and is regarded as a senior Companions of the Prophet, companion and father-in-law of the Islamic prophet Muhammad. Initially, Umar opposed Muhammad, who was his distant Qurayshite kinsman. However, after converting to Islam in 616, he became the first Muslims, Muslim to openly pray at the Kaaba. He participated in nearly all of Muhammad’s List of expeditions of Muhammad, battles and expeditions, and Muhammad conferred upon him the title ''al-Fārūq'' ("the Distinguisher") for his sound judgement. After Muhammad’s death in June 632, Umar pledged allegiance to Abu Bakr as the first caliph and served as his chief adviser. In 634, shortly before his death, Abu Bakr nominated Umar as his successor. During Umar’s reign, the caliphate expanded at an unprecedented rate, conquering the Sasanian Empire and more than two-t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Omar M
Umar ibn al-Khattab (; ), also spelled Omar, was the second Rashidun caliph, ruling from August 634 until his assassination in 644. He succeeded Abu Bakr () and is regarded as a senior companion and father-in-law of the Islamic prophet Muhammad. Initially, Umar opposed Muhammad, who was his distant Qurayshite kinsman. However, after converting to Islam in 616, he became the first Muslim to openly pray at the Kaaba. He participated in nearly all of Muhammad’s battles and expeditions, and Muhammad conferred upon him the title ''al-Fārūq'' ("the Distinguisher") for his sound judgement. After Muhammad’s death in June 632, Umar pledged allegiance to Abu Bakr as the first caliph and served as his chief adviser. In 634, shortly before his death, Abu Bakr nominated Umar as his successor. During Umar’s reign, the caliphate expanded at an unprecedented rate, conquering the Sasanian Empire and more than two-thirds of the Byzantine Empire. His campaigns against the Sasanians ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal–organic Framework
Metal–organic frameworks (MOFs) are a class of porous polymers consisting of metal cluster compound, clusters (also known as Secondary Building Units - SBUs) coordinated to organic compound, organic ligands to form one-, two- or three-dimensional structures. The organic ligands included are sometimes referred to as "struts" or "linkers", one example being terephthalic acid, 1,4-benzenedicarboxylic acid (BDC). MOFs are classified as reticular materials. More formally, a metal–organic framework is a potentially porous extended structure made from metal ions and organic linkers. An extended structure is a structure whose sub-units occur in a constant ratio and are arranged in a repeating pattern. MOFs are a subclass of coordination networks, which is a coordination compound extending, through repeating coordination entities, in one dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or a coordination compound extending through repeating c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covalent Organic Framework
Covalent organic frameworks (COFs) are a class of porous polymers that form two- or three-dimensional structures through reactions between organic precursors resulting in strong, covalent bonds to afford porous, stable, and crystalline materials. COFs emerged as a field from the overarching domain of organic materials as researchers optimized both synthetic control and precursor selection. These improvements to coordination chemistry enabled non-porous and amorphous organic materials such as organic polymers to advance into the construction of porous, crystalline materials with rigid structures that granted exceptional material stability in a wide range of solvents and conditions. Through the development of reticular chemistry, precise synthetic control was achieved and resulted in ordered, nano-porous structures with highly preferential structural orientation and properties which could be synergistically enhanced and amplified. With judicious selection of COF secondary building unit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeolitic Imidazolate Framework
Zeolitic imidazolate frameworks (ZIFs) are a class of metal-organic frameworks (MOFs) that are topologically isomorphic with zeolites. ZIFs are composed of tetrahedrally-coordinated transition metal ions (e.g. Fe, Co, Zn) connected by imidazolate linkers. Since the metal-imidazole-metal angle is similar to the 145° Si-O-Si angle in zeolites, ZIFs have zeolite-like topologies. As of 2010, 105 ZIF topologies have been reported in the literature. Due to their robust porosity, resistance to thermal changes, and chemical stability, ZIFs are being investigated for applications such as carbon dioxide capture. ZIF glasses can be synthesized by the melt-quench method, and the first melt-quenched ZIF glass was firstly made and reported by Bennett et al. back in 2015. ZIFs remain porous even after forming glasses, recent studies have revealed that the linker modification can really modulate the melting behaviour of ZIFs. ZIF glasses are a newly discovered type of material that has be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Protective Equipment
Personal protective equipment (PPE) is protective clothing, helmets, goggles, or other garments or equipment designed to protect the wearer's body from injury or infection. The hazards addressed by protective equipment include physical, electrical, heat, chemical, biohazards, and airborne particulate matter. Protective equipment may be worn for job-related occupational safety and health purposes, as well as for sports and other recreational activities. ''Protective clothing'' is applied to traditional categories of clothing, and ''protective gear'' applies to items such as pads, guards, shields, or masks, and others. PPE suits can be similar in appearance to a cleanroom suit. The purpose of personal protective equipment is to reduce employee exposure to hazards when engineering controls and administrative controls are not feasible or effective to reduce these risks to acceptable levels. PPE is needed when there are hazards present. PPE has the serious limitation that it d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Structure Of MOF-5
''The'' is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pronoun ''thee' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
