Lanthanide Contraction
Lanthanide Contraction - Related Videos
13:21
Preparation, Purification, and Characterization of Lanthanide Complexes for Use as Contrast Agents for Magnetic Resonance Imaging
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Cited by 9 •
2011
We demonstrate the metalation, purification, and characterization of lanthanide complexes. The complexes described here can be conjugated to macromolecules to enable tracking of these molecules using magnetic resonance imaging.
01:15
Muscle Contraction
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2025
In skeletal muscles, acetylcholine is released by nerve terminals at the motor end plate—the point of synaptic communication between motor neurons and muscle fibers. Binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive muscle...
01:10
Muscle Contraction
0 Views •
2023
In skeletal muscles, acetylcholine is released by nerve terminals at the motor endplate—the point of synaptic communication between motor neurons and muscle fibers. The binding of acetylcholine to its receptors on the sarcolemma allows entry of sodium ions into the cell and triggers an action potential in the muscle cell. Thus, electrical signals from the brain are transmitted to the muscle. Subsequently, the enzyme acetylcholinesterase breaks down acetylcholine to prevent excessive muscle...
02:08
Assessing Muscle Contraction with Neuromuscular Blocker Treatment
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2025
This video demonstrates assessing the muscle using cultured motor neurons, Schwann cells, and myotubes, followed by treatment with a neuromuscular blocker to inhibit contraction. Color-coded time-motion graphics show a color-coded time-motion graphic. Red indicates the fastest movement, and blue indicates the slowest.
11:38
Preparation of Complaint Matrices for Quantifying Cellular Contraction
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Cited by 115 •
2010
In this video, we demonstrate the experimental techniques used to fabricate compliant, extracellular matrix (ECM) coated substrates suitable for cell culture, and which are amenable to traction force microscopy and observing effects of ECM stiffness on cell behavior.
FAQs
The 4f electrons do not offset the increasing nuclear charge as effectively as electrons in more penetrating orbitals. Consequently, outer electrons experience a stronger effective attraction to the nucleus as protons are added across the series. This imperfect shielding accounts for the systematic changes in size and helps explain why lanthanide chemistry changes gradually rather than remaining identical throughout the series.
As nuclear attraction strengthens across the lanthanide series, removing an electron becomes more difficult, and the changing ionic dimensions affect bonding interactions. Smaller ions can alter bond distances, coordination geometry, and the stability of complexes. These effects connect an electronic trend to observable differences in lanthanide compounds, including changes in compound basicity and coordination behavior.
Lanthanide Contraction helps explain why zirconium and hafnium, although located in different periods, have closely similar sizes and chemical behavior. The contraction through the lanthanide series offsets some of the size increase expected for the heavier element. Their comparable dimensions therefore influence how they participate in inorganic chemistry and help account for similarities between their compounds.
Changes in ionic size influence several related properties rather than a single reaction outcome. Coordination geometry can shift as available space around the ion changes, while complex stability depends on how effectively ligands interact with the ion. The same size trend also affects the basicity of lanthanide compounds, giving researchers multiple chemical observations with which to assess its consequences.
The trend provides a framework for anticipating differences in ionic dimensions before selecting lanthanide components for inorganic synthesis or materials chemistry. Those dimensional changes can guide expectations about bonding, coordination geometry, complex stability, and compound basicity. In practice, this context helps chemists interpret why related lanthanide-containing compounds may display different structures or chemical behavior.
Rare-earth elements can show closely related chemical behavior, yet their progressively changing ionic dimensions influence bonding and complex stability. These differences provide chemically useful distinctions within a group that otherwise behaves similarly. Understanding the contraction therefore supports interpretation of separation strategies and explains why small size-dependent changes can matter when working with mixtures of rare-earth elements.